diff --git a/src/USER-INTEL/pair_lj_charmm_coul_charmm_intel.cpp b/src/USER-INTEL/pair_lj_charmm_coul_charmm_intel.cpp
index ff8a9869b7..2078e5277b 100644
--- a/src/USER-INTEL/pair_lj_charmm_coul_charmm_intel.cpp
+++ b/src/USER-INTEL/pair_lj_charmm_coul_charmm_intel.cpp
@@ -12,19 +12,21 @@
    Contributing author: W. Michael Brown (Intel)
 ------------------------------------------------------------------------- */
 
-#include <cmath>
 #include "pair_lj_charmm_coul_charmm_intel.h"
+
 #include "atom.h"
 #include "comm.h"
 #include "force.h"
-#include "group.h"
 #include "memory.h"
 #include "modify.h"
 #include "neighbor.h"
 #include "neigh_list.h"
 #include "neigh_request.h"
-#include "memory.h"
 #include "suffix.h"
+
+#include <cmath>
+#include <cstring>
+
 using namespace LAMMPS_NS;
 
 #define LJ_T typename IntelBuffers<flt_t,flt_t>::vec4_t
diff --git a/src/atom.cpp b/src/atom.cpp
index ccd93401fb..864c7af638 100644
--- a/src/atom.cpp
+++ b/src/atom.cpp
@@ -12,7 +12,7 @@
 ------------------------------------------------------------------------- */
 
 #include "atom.h"
-#include "style_atom.h"
+#include "style_atom.h"  // IWYU pragma: keep
 
 #include "comm.h"
 #include "compute.h"
diff --git a/src/atom_vec_body.cpp b/src/atom_vec_body.cpp
index 871f40084d..608c803e20 100644
--- a/src/atom_vec_body.cpp
+++ b/src/atom_vec_body.cpp
@@ -12,7 +12,7 @@
 ------------------------------------------------------------------------- */
 
 #include "atom_vec_body.h"
-#include "style_body.h"
+#include "style_body.h"    // IWYU pragma: keep
 
 #include "atom.h"
 #include "body.h"
diff --git a/src/atom_vec_hybrid.cpp b/src/atom_vec_hybrid.cpp
index 5c37be4aa4..7a8c73570d 100644
--- a/src/atom_vec_hybrid.cpp
+++ b/src/atom_vec_hybrid.cpp
@@ -595,7 +595,7 @@ void AtomVecHybrid::build_styles()
   nallstyles = 0;
 #define ATOM_CLASS
 #define AtomStyle(key,Class) nallstyles++;
-#include "style_atom.h"
+#include "style_atom.h"   // IWYU pragma: keep
 #undef AtomStyle
 #undef ATOM_CLASS
 
@@ -609,7 +609,7 @@ void AtomVecHybrid::build_styles()
   allstyles[nallstyles] = new char[n];      \
   strcpy(allstyles[nallstyles],#key);       \
   nallstyles++;
-#include "style_atom.h"
+#include "style_atom.h"  // IWYU pragma: keep
 #undef AtomStyle
 #undef ATOM_CLASS
 }
diff --git a/src/create_atoms.cpp b/src/create_atoms.cpp
index b121edb5b2..7e84e9cce0 100644
--- a/src/create_atoms.cpp
+++ b/src/create_atoms.cpp
@@ -16,31 +16,27 @@
 ------------------------------------------------------------------------- */
 
 #include "create_atoms.h"
-#include <mpi.h>
-#include <cstring>
+
 #include "atom.h"
 #include "atom_vec.h"
-#include "molecule.h"
 #include "comm.h"
-#include "irregular.h"
-#include "modify.h"
-#include "force.h"
-#include "special.h"
 #include "domain.h"
-#include "lattice.h"
-#include "region.h"
-#include "input.h"
-#include "variable.h"
-#include "random_park.h"
-#include "random_mars.h"
-#include "math_extra.h"
-#include "math_const.h"
 #include "error.h"
+#include "input.h"
+#include "irregular.h"
+#include "lattice.h"
+#include "math_const.h"
+#include "math_extra.h"
 #include "memory.h"
+#include "modify.h"
+#include "molecule.h"
+#include "random_mars.h"
+#include "random_park.h"
+#include "region.h"
+#include "special.h"
+#include "variable.h"
 
-#include <string>
-#include "utils.h"
-#include "fmt/format.h"
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace MathConst;
diff --git a/src/create_bonds.cpp b/src/create_bonds.cpp
index 4261d9f766..9e3eb65801 100644
--- a/src/create_bonds.cpp
+++ b/src/create_bonds.cpp
@@ -18,21 +18,19 @@
 ------------------------------------------------------------------------- */
 
 #include "create_bonds.h"
-#include <mpi.h>
-#include <cstring>
-#include <string>
+
 #include "atom.h"
-#include "domain.h"
-#include "force.h"
-#include "neighbor.h"
-#include "neigh_request.h"
-#include "neigh_list.h"
 #include "comm.h"
-#include "group.h"
-#include "special.h"
+#include "domain.h"
 #include "error.h"
-#include "utils.h"
-#include "fmt/format.h"
+#include "force.h"
+#include "group.h"
+#include "neigh_list.h"
+#include "neigh_request.h"
+#include "neighbor.h"
+#include "special.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/domain.cpp b/src/domain.cpp
index f54df1f382..984c735a20 100644
--- a/src/domain.cpp
+++ b/src/domain.cpp
@@ -16,6 +16,7 @@
 ------------------------------------------------------------------------- */
 
 #include "domain.h"
+#include "style_region.h"   // IWYU pragma: keep
 
 #include "atom.h"
 #include "atom_vec.h"
@@ -31,7 +32,6 @@
 #include "molecule.h"
 #include "output.h"
 #include "region.h"
-#include "style_region.h"
 #include "thermo.h"
 #include "universe.h"
 #include "update.h"
@@ -106,7 +106,8 @@ Domain::Domain(LAMMPS *lmp) : Pointers(lmp)
 #define REGION_CLASS
 #define RegionStyle(key,Class) \
   (*region_map)[#key] = &region_creator<Class>;
-#include "style_region.h"
+#include "style_region.h"   // IWYU pragma: keep
+
 #undef RegionStyle
 #undef REGION_CLASS
 }
diff --git a/src/dump_local.cpp b/src/dump_local.cpp
index 6f824e5559..a71166ec57 100644
--- a/src/dump_local.cpp
+++ b/src/dump_local.cpp
@@ -13,18 +13,15 @@
 
 #include "dump_local.h"
 
-#include <cstring>
-
-#include "modify.h"
-#include "fix.h"
 #include "compute.h"
 #include "domain.h"
-#include "update.h"
-#include "input.h"
-#include "memory.h"
 #include "error.h"
-#include "force.h"
+#include "fix.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
 
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/dump_movie.cpp b/src/dump_movie.cpp
index a37341a15c..5f6d0b80d7 100644
--- a/src/dump_movie.cpp
+++ b/src/dump_movie.cpp
@@ -16,11 +16,11 @@
 ------------------------------------------------------------------------- */
 
 #include "dump_movie.h"
-#include <cstring>
+
 #include "comm.h"
-#include "force.h"
 #include "error.h"
 
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/error.cpp b/src/error.cpp
index 7458f816c0..0ea218887f 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -12,16 +12,11 @@
 ------------------------------------------------------------------------- */
 
 #include "error.h"
-#include <mpi.h>
-#include <cstdlib>
-#include <cstring>
-#include <string>
-#include "universe.h"
-#include "output.h"
-#include "input.h"
+
 #include "accelerator_kokkos.h"
-#include "utils.h"
-#include "fmt/format.h"
+#include "input.h"
+#include "output.h"
+#include "universe.h"
 
 #if defined(LAMMPS_EXCEPTIONS)
 #include "update.h"
diff --git a/src/error.h b/src/error.h
index 40c1559464..dedebc4148 100644
--- a/src/error.h
+++ b/src/error.h
@@ -15,7 +15,6 @@
 #define LMP_ERROR_H
 
 #include "pointers.h"
-#include <string>
 
 #ifdef LAMMPS_EXCEPTIONS
 #include "exceptions.h"
diff --git a/src/finish.cpp b/src/finish.cpp
index 51f886b5db..7990a3c141 100644
--- a/src/finish.cpp
+++ b/src/finish.cpp
@@ -12,28 +12,26 @@
 ------------------------------------------------------------------------- */
 
 #include "finish.h"
-#include <mpi.h>
-#include <cmath>
-#include <cstdlib>
-#include <cstring>
+
 #include "accelerator_kokkos.h"
 #include "atom.h"
 #include "atom_vec.h"
-#include "molecule.h"
 #include "comm.h"
+#include "error.h"
 #include "force.h"
 #include "kspace.h"
-#include "update.h"
+#include "memory.h"
 #include "min.h"
-#include "neighbor.h"
+#include "molecule.h"
 #include "neigh_list.h"
 #include "neigh_request.h"
-#include "memory.h"
-#include "error.h"
+#include "neighbor.h"
 #include "timer.h"
 #include "universe.h"
-#include "utils.h"
-#include "fmt/format.h"
+#include "update.h"
+
+#include <cmath>
+#include <cstring>
 
 #ifdef LMP_USER_OMP
 #include "modify.h"
diff --git a/src/fix.cpp b/src/fix.cpp
index 549208a0ce..03313739a1 100644
--- a/src/fix.cpp
+++ b/src/fix.cpp
@@ -12,14 +12,15 @@
 ------------------------------------------------------------------------- */
 
 #include "fix.h"
+
+#include "atom.h"
+#include "atom_masks.h"
+#include "error.h"
+#include "group.h"
+#include "memory.h"
+
 #include <cstring>
 #include <cctype>
-#include "atom.h"
-#include "group.h"
-#include "force.h"
-#include "atom_masks.h"
-#include "memory.h"
-#include "error.h"
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_addforce.cpp b/src/fix_addforce.cpp
index 08025b8392..0983728ea9 100644
--- a/src/fix_addforce.cpp
+++ b/src/fix_addforce.cpp
@@ -13,20 +13,19 @@
 
 #include "fix_addforce.h"
 
-#include <cstring>
-
 #include "atom.h"
 #include "atom_masks.h"
-#include "update.h"
-#include "modify.h"
 #include "domain.h"
+#include "error.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
 #include "region.h"
 #include "respa.h"
-#include "input.h"
+#include "update.h"
 #include "variable.h"
-#include "memory.h"
-#include "error.h"
-#include "force.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_ave_atom.cpp b/src/fix_ave_atom.cpp
index 838d2487b2..da009c55d5 100644
--- a/src/fix_ave_atom.cpp
+++ b/src/fix_ave_atom.cpp
@@ -13,17 +13,16 @@
 
 #include "fix_ave_atom.h"
 
-#include <cstring>
 #include "atom.h"
-#include "update.h"
-#include "modify.h"
 #include "compute.h"
-#include "input.h"
-#include "variable.h"
-#include "memory.h"
 #include "error.h"
-#include "force.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
 
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_ave_correlate.cpp b/src/fix_ave_correlate.cpp
index 92a01932e7..031dfc26bf 100644
--- a/src/fix_ave_correlate.cpp
+++ b/src/fix_ave_correlate.cpp
@@ -19,19 +19,16 @@
 
 #include "fix_ave_correlate.h"
 
+#include "compute.h"
+#include "error.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
 
 #include <cstring>
 #include <unistd.h>
-#include "update.h"
-#include "modify.h"
-#include "compute.h"
-#include "input.h"
-#include "variable.h"
-#include "memory.h"
-#include "error.h"
-#include "force.h"
-
-
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_ave_histo.cpp b/src/fix_ave_histo.cpp
index 790fb9a1d4..3a9346498f 100644
--- a/src/fix_ave_histo.cpp
+++ b/src/fix_ave_histo.cpp
@@ -13,20 +13,17 @@
 
 #include "fix_ave_histo.h"
 
+#include "atom.h"
+#include "compute.h"
+#include "error.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
 
 #include <cstring>
 #include <unistd.h>
-#include "atom.h"
-#include "update.h"
-#include "modify.h"
-#include "compute.h"
-#include "input.h"
-#include "variable.h"
-#include "memory.h"
-#include "error.h"
-#include "force.h"
-
-
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_ave_time.cpp b/src/fix_ave_time.cpp
index e83a3f60f5..9c493b9846 100644
--- a/src/fix_ave_time.cpp
+++ b/src/fix_ave_time.cpp
@@ -17,19 +17,16 @@
 
 #include "fix_ave_time.h"
 
+#include "compute.h"
+#include "error.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
 
 #include <cstring>
 #include <unistd.h>
-#include "update.h"
-#include "force.h"
-#include "modify.h"
-#include "compute.h"
-#include "input.h"
-#include "variable.h"
-#include "memory.h"
-#include "error.h"
-
-
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_aveforce.cpp b/src/fix_aveforce.cpp
index 7b8dc28cb3..00ec0d67ba 100644
--- a/src/fix_aveforce.cpp
+++ b/src/fix_aveforce.cpp
@@ -13,17 +13,17 @@
 
 #include "fix_aveforce.h"
 
-#include <cstring>
 #include "atom.h"
-#include "update.h"
-#include "modify.h"
 #include "domain.h"
+#include "error.h"
+#include "input.h"
+#include "modify.h"
 #include "region.h"
 #include "respa.h"
-#include "input.h"
+#include "update.h"
 #include "variable.h"
-#include "error.h"
-#include "force.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_controller.cpp b/src/fix_controller.cpp
index 190a8bcd7d..92fd42f3db 100644
--- a/src/fix_controller.cpp
+++ b/src/fix_controller.cpp
@@ -13,14 +13,14 @@
 
 #include "fix_controller.h"
 
-#include <cstring>
-#include "force.h"
-#include "update.h"
-#include "modify.h"
 #include "compute.h"
-#include "input.h"
-#include "variable.h"
 #include "error.h"
+#include "input.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_drag.cpp b/src/fix_drag.cpp
index 25e21c5ee1..2400014569 100644
--- a/src/fix_drag.cpp
+++ b/src/fix_drag.cpp
@@ -13,14 +13,14 @@
 
 #include "fix_drag.h"
 
-#include <cmath>
-#include <cstring>
 #include "atom.h"
-#include "update.h"
-#include "respa.h"
 #include "domain.h"
 #include "error.h"
-#include "force.h"
+#include "respa.h"
+#include "update.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_external.cpp b/src/fix_external.cpp
index 5d810ff38b..1db7e15295 100644
--- a/src/fix_external.cpp
+++ b/src/fix_external.cpp
@@ -12,12 +12,13 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_external.h"
-#include <cstring>
+
 #include "atom.h"
-#include "update.h"
-#include "memory.h"
 #include "error.h"
-#include "force.h"
+#include "memory.h"
+#include "update.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_gravity.cpp b/src/fix_gravity.cpp
index 88ce2faaad..6dff937385 100644
--- a/src/fix_gravity.cpp
+++ b/src/fix_gravity.cpp
@@ -13,18 +13,18 @@
 
 #include "fix_gravity.h"
 
+#include "atom.h"
+#include "domain.h"
+#include "error.h"
+#include "input.h"
+#include "math_const.h"
+#include "modify.h"
+#include "respa.h"
+#include "update.h"
+#include "variable.h"
+
 #include <cmath>
 #include <cstring>
-#include "atom.h"
-#include "update.h"
-#include "domain.h"
-#include "respa.h"
-#include "modify.h"
-#include "input.h"
-#include "variable.h"
-#include "math_const.h"
-#include "error.h"
-#include "force.h"
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_group.cpp b/src/fix_group.cpp
index 5e2a12c988..bb51fafa12 100644
--- a/src/fix_group.cpp
+++ b/src/fix_group.cpp
@@ -12,20 +12,21 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_group.h"
-#include <cstring>
-#include "group.h"
-#include "update.h"
+
 #include "atom.h"
-#include "force.h"
 #include "comm.h"
 #include "domain.h"
-#include "region.h"
-#include "modify.h"
-#include "respa.h"
-#include "input.h"
-#include "variable.h"
-#include "memory.h"
 #include "error.h"
+#include "group.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "region.h"
+#include "respa.h"
+#include "update.h"
+#include "variable.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_halt.cpp b/src/fix_halt.cpp
index 39591cd5f1..f8222e3ece 100644
--- a/src/fix_halt.cpp
+++ b/src/fix_halt.cpp
@@ -13,21 +13,19 @@
 
 #include "fix_halt.h"
 
+#include "atom.h"
+#include "comm.h"
+#include "error.h"
+#include "input.h"
+#include "modify.h"
+#include "neighbor.h"
+#include "timer.h"
+#include "update.h"
+#include "variable.h"
+
 #include <cmath>
 #include <cstring>
 
-#include "update.h"
-#include "force.h"
-#include "input.h"
-#include "variable.h"
-#include "atom.h"
-#include "neighbor.h"
-#include "modify.h"
-#include "comm.h"
-#include "timer.h"
-#include "error.h"
-
-
 using namespace LAMMPS_NS;
 using namespace FixConst;
 
diff --git a/src/fix_indent.cpp b/src/fix_indent.cpp
index f42e0a527b..ae58f27913 100644
--- a/src/fix_indent.cpp
+++ b/src/fix_indent.cpp
@@ -17,18 +17,18 @@
 
 #include "fix_indent.h"
 
-#include <cmath>
-#include <cstring>
 #include "atom.h"
-#include "input.h"
-#include "variable.h"
 #include "domain.h"
+#include "error.h"
+#include "input.h"
 #include "lattice.h"
-#include "update.h"
 #include "modify.h"
 #include "respa.h"
-#include "error.h"
-#include "force.h"
+#include "update.h"
+#include "variable.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_lineforce.cpp b/src/fix_lineforce.cpp
index 0287c8c0db..cacec13302 100644
--- a/src/fix_lineforce.cpp
+++ b/src/fix_lineforce.cpp
@@ -12,13 +12,14 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_lineforce.h"
+
+#include "atom.h"
+#include "error.h"
+#include "respa.h"
+#include "update.h"
+
 #include <cmath>
 #include <cstring>
-#include "atom.h"
-#include "update.h"
-#include "respa.h"
-#include "error.h"
-#include "force.h"
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_momentum.cpp b/src/fix_momentum.cpp
index 4af2ed3961..259099e07c 100644
--- a/src/fix_momentum.cpp
+++ b/src/fix_momentum.cpp
@@ -13,13 +13,13 @@
 
 #include "fix_momentum.h"
 
-#include <cmath>
-#include <cstring>
 #include "atom.h"
 #include "domain.h"
-#include "group.h"
 #include "error.h"
-#include "force.h"
+#include "group.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_nh_sphere.cpp b/src/fix_nh_sphere.cpp
index 1ff3fc2d4d..d60798e007 100644
--- a/src/fix_nh_sphere.cpp
+++ b/src/fix_nh_sphere.cpp
@@ -16,15 +16,16 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_nh_sphere.h"
-#include <cmath>
-#include <cstring>
+
 #include "atom.h"
-#include "atom_vec.h"
+#include "domain.h"
 #include "error.h"
 #include "force.h"
-#include "domain.h"
-#include "math_vector.h"
 #include "math_extra.h"
+#include "math_vector.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_nve_sphere.cpp b/src/fix_nve_sphere.cpp
index c0fea17c2b..87fba3eca3 100644
--- a/src/fix_nve_sphere.cpp
+++ b/src/fix_nve_sphere.cpp
@@ -12,15 +12,16 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_nve_sphere.h"
-#include <cmath>
-#include <cstring>
+
 #include "atom.h"
 #include "domain.h"
-#include "atom_vec.h"
-#include "force.h"
 #include "error.h"
-#include "math_vector.h"
+#include "force.h"
 #include "math_extra.h"
+#include "math_vector.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_planeforce.cpp b/src/fix_planeforce.cpp
index 9434a4b348..2e3bcadd69 100644
--- a/src/fix_planeforce.cpp
+++ b/src/fix_planeforce.cpp
@@ -12,13 +12,14 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_planeforce.h"
+
+#include "atom.h"
+#include "error.h"
+#include "respa.h"
+#include "update.h"
+
 #include <cmath>
 #include <cstring>
-#include "atom.h"
-#include "update.h"
-#include "respa.h"
-#include "error.h"
-#include "force.h"
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_print.cpp b/src/fix_print.cpp
index 017ae48925..78fceea184 100644
--- a/src/fix_print.cpp
+++ b/src/fix_print.cpp
@@ -13,16 +13,14 @@
 
 #include "fix_print.h"
 
-#include <cstring>
-#include "update.h"
-#include "input.h"
-#include "modify.h"
-#include "variable.h"
-#include "memory.h"
 #include "error.h"
-#include "force.h"
-
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
 
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_read_restart.cpp b/src/fix_read_restart.cpp
index c1c0150177..2e10b15ffa 100644
--- a/src/fix_read_restart.cpp
+++ b/src/fix_read_restart.cpp
@@ -12,9 +12,9 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_read_restart.h"
+
 #include "atom.h"
 #include "memory.h"
-#include "force.h"
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_recenter.cpp b/src/fix_recenter.cpp
index 8997e4b805..3f9eec9ee4 100644
--- a/src/fix_recenter.cpp
+++ b/src/fix_recenter.cpp
@@ -16,18 +16,19 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_recenter.h"
-#include <cmath>
-#include <cstring>
+
 #include "atom.h"
-#include "group.h"
-#include "update.h"
+#include "comm.h"
 #include "domain.h"
+#include "error.h"
+#include "group.h"
 #include "lattice.h"
 #include "modify.h"
-#include "comm.h"
 #include "respa.h"
-#include "error.h"
-#include "force.h"
+#include "update.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_respa.cpp b/src/fix_respa.cpp
index 459b30c1b2..b116f8ccac 100644
--- a/src/fix_respa.cpp
+++ b/src/fix_respa.cpp
@@ -12,11 +12,12 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_respa.h"
-#include <cstring>
+
 #include "atom.h"
-#include "force.h"
 #include "memory.h"
 
+#include <cstring>
+
 using namespace LAMMPS_NS;
 using namespace FixConst;
 
diff --git a/src/fix_setforce.cpp b/src/fix_setforce.cpp
index 329edbd6ef..229890c5df 100644
--- a/src/fix_setforce.cpp
+++ b/src/fix_setforce.cpp
@@ -13,18 +13,18 @@
 
 #include "fix_setforce.h"
 
-#include <cstring>
 #include "atom.h"
-#include "update.h"
-#include "modify.h"
 #include "domain.h"
+#include "error.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
 #include "region.h"
 #include "respa.h"
-#include "input.h"
+#include "update.h"
 #include "variable.h"
-#include "memory.h"
-#include "error.h"
-#include "force.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_spring.cpp b/src/fix_spring.cpp
index 1bd76f5c55..2d695add26 100644
--- a/src/fix_spring.cpp
+++ b/src/fix_spring.cpp
@@ -16,14 +16,15 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_spring.h"
+
+#include "atom.h"
+#include "error.h"
+#include "group.h"
+#include "respa.h"
+#include "update.h"
+
 #include <cmath>
 #include <cstring>
-#include "atom.h"
-#include "update.h"
-#include "respa.h"
-#include "force.h"
-#include "group.h"
-#include "error.h"
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_spring_chunk.cpp b/src/fix_spring_chunk.cpp
index 778a6f0c43..d8de88bd63 100644
--- a/src/fix_spring_chunk.cpp
+++ b/src/fix_spring_chunk.cpp
@@ -12,18 +12,19 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_spring_chunk.h"
-#include <cmath>
-#include <cstring>
+
 #include "atom.h"
 #include "comm.h"
-#include "update.h"
-#include "force.h"
-#include "respa.h"
-#include "modify.h"
 #include "compute_chunk_atom.h"
 #include "compute_com_chunk.h"
-#include "memory.h"
 #include "error.h"
+#include "memory.h"
+#include "modify.h"
+#include "respa.h"
+#include "update.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_spring_rg.cpp b/src/fix_spring_rg.cpp
index e3ba935340..5715e7eb88 100644
--- a/src/fix_spring_rg.cpp
+++ b/src/fix_spring_rg.cpp
@@ -17,15 +17,16 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_spring_rg.h"
-#include <cstring>
+
 #include "atom.h"
 #include "comm.h"
-#include "update.h"
-#include "group.h"
-#include "respa.h"
 #include "domain.h"
 #include "error.h"
-#include "force.h"
+#include "group.h"
+#include "respa.h"
+#include "update.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_spring_self.cpp b/src/fix_spring_self.cpp
index 112b675826..8e7b3eb925 100644
--- a/src/fix_spring_self.cpp
+++ b/src/fix_spring_self.cpp
@@ -17,14 +17,14 @@
 
 #include "fix_spring_self.h"
 
-#include <cstring>
 #include "atom.h"
-#include "update.h"
 #include "domain.h"
-#include "respa.h"
-#include "memory.h"
 #include "error.h"
-#include "force.h"
+#include "memory.h"
+#include "respa.h"
+#include "update.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_store.cpp b/src/fix_store.cpp
index 8ce94fb54a..3eb2075250 100644
--- a/src/fix_store.cpp
+++ b/src/fix_store.cpp
@@ -12,12 +12,13 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_store.h"
-#include <cstring>
+
 #include "atom.h"
 #include "comm.h"
-#include "force.h"
-#include "memory.h"
 #include "error.h"
+#include "memory.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_store_state.cpp b/src/fix_store_state.cpp
index e18317ba03..fd4563b7ad 100644
--- a/src/fix_store_state.cpp
+++ b/src/fix_store_state.cpp
@@ -13,19 +13,19 @@
 
 #include "fix_store_state.h"
 
-#include <cstring>
 #include "atom.h"
-#include "domain.h"
-#include "update.h"
-#include "group.h"
-#include "modify.h"
 #include "compute.h"
-#include "fix.h"
-#include "input.h"
-#include "variable.h"
-#include "memory.h"
+#include "domain.h"
 #include "error.h"
-#include "force.h"
+#include "fix.h"
+#include "group.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_vector.cpp b/src/fix_vector.cpp
index 8af098d66f..6bcdfe948e 100644
--- a/src/fix_vector.cpp
+++ b/src/fix_vector.cpp
@@ -13,15 +13,15 @@
 
 #include "fix_vector.h"
 
-#include <cstring>
-#include "update.h"
-#include "force.h"
-#include "modify.h"
 #include "compute.h"
-#include "input.h"
-#include "variable.h"
-#include "memory.h"
 #include "error.h"
+#include "input.h"
+#include "memory.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_viscous.cpp b/src/fix_viscous.cpp
index 7d532d832d..08649280d8 100644
--- a/src/fix_viscous.cpp
+++ b/src/fix_viscous.cpp
@@ -12,12 +12,13 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_viscous.h"
-#include <cstring>
+
 #include "atom.h"
-#include "update.h"
-#include "respa.h"
 #include "error.h"
-#include "force.h"
+#include "respa.h"
+#include "update.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_wall.cpp b/src/fix_wall.cpp
index e2237d074d..cb822f1090 100644
--- a/src/fix_wall.cpp
+++ b/src/fix_wall.cpp
@@ -13,17 +13,16 @@
 
 #include "fix_wall.h"
 
-#include <cstring>
-#include "input.h"
-#include "variable.h"
 #include "domain.h"
+#include "error.h"
+#include "input.h"
 #include "lattice.h"
-#include "update.h"
 #include "modify.h"
 #include "respa.h"
-#include "error.h"
-#include "force.h"
+#include "update.h"
+#include "variable.h"
 
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_wall_reflect.cpp b/src/fix_wall_reflect.cpp
index 061083e55c..227ef66564 100644
--- a/src/fix_wall_reflect.cpp
+++ b/src/fix_wall_reflect.cpp
@@ -12,17 +12,18 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_wall_reflect.h"
-#include <cstring>
+
 #include "atom.h"
 #include "comm.h"
-#include "update.h"
-#include "modify.h"
 #include "domain.h"
-#include "force.h"
-#include "lattice.h"
-#include "input.h"
-#include "variable.h"
 #include "error.h"
+#include "input.h"
+#include "lattice.h"
+#include "modify.h"
+#include "update.h"
+#include "variable.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/fix_wall_region.cpp b/src/fix_wall_region.cpp
index 76b2cd11fa..fc3735cfbf 100644
--- a/src/fix_wall_region.cpp
+++ b/src/fix_wall_region.cpp
@@ -13,16 +13,16 @@
 
 #include "fix_wall_region.h"
 
-#include <cmath>
-#include <cstring>
 #include "atom.h"
 #include "domain.h"
-#include "region.h"
-#include "force.h"
-#include "update.h"
-#include "respa.h"
 #include "error.h"
 #include "math_const.h"
+#include "region.h"
+#include "respa.h"
+#include "update.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/force.cpp b/src/force.cpp
index 10b82afabe..8eef7a4224 100644
--- a/src/force.cpp
+++ b/src/force.cpp
@@ -12,31 +12,29 @@
 ------------------------------------------------------------------------- */
 
 #include "force.h"
-#include <cstdlib>
-#include <cstring>
-#include <cctype>
-#include <string>
-#include "style_bond.h"
-#include "style_angle.h"
-#include "style_dihedral.h"
-#include "style_improper.h"
-#include "style_pair.h"
-#include "style_kspace.h"
+#include "style_angle.h"       // IWYU pragma: keep
+#include "style_bond.h"        // IWYU pragma: keep
+#include "style_dihedral.h"    // IWYU pragma: keep
+#include "style_improper.h"    // IWYU pragma: keep
+#include "style_kspace.h"      // IWYU pragma: keep
+#include "style_pair.h"        // IWYU pragma: keep
+
+#include "angle.h"
 #include "atom.h"
+#include "bond.h"
+#include "bond_hybrid.h"
 #include "comm.h"
+#include "dihedral.h"
+#include "error.h"
+#include "improper.h"
+#include "kspace.h"
 #include "pair.h"
 #include "pair_hybrid.h"
 #include "pair_hybrid_overlay.h"
-#include "bond.h"
-#include "bond_hybrid.h"
-#include "angle.h"
-#include "dihedral.h"
-#include "improper.h"
-#include "kspace.h"
-#include "error.h"
 #include "update.h"
-#include "utils.h"
-#include "fmt/format.h"
+
+#include <cctype>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/force.h b/src/force.h
index d7824ea90e..999e9650aa 100644
--- a/src/force.h
+++ b/src/force.h
@@ -15,8 +15,8 @@
 #define LMP_FORCE_H
 
 #include "pointers.h"
+
 #include <map>
-#include <string>
 
 namespace LAMMPS_NS {
 
diff --git a/src/group.cpp b/src/group.cpp
index 2377f028bd..ee96c20f47 100644
--- a/src/group.cpp
+++ b/src/group.cpp
@@ -12,30 +12,27 @@
 ------------------------------------------------------------------------- */
 
 #include "group.h"
-#include <mpi.h>
-#include <cmath>
-#include <cstring>
-#include <string>
-#include <utility>
-#include "domain.h"
+
 #include "atom.h"
-#include "force.h"
 #include "comm.h"
-#include "region.h"
-#include "modify.h"
-#include "fix.h"
 #include "compute.h"
-#include "output.h"
-#include "input.h"
-#include "variable.h"
+#include "domain.h"
 #include "dump.h"
+#include "error.h"
+#include "fix.h"
+#include "force.h"
+#include "input.h"
 #include "math_extra.h"
 #include "memory.h"
-#include "error.h"
-#include "utils.h"
-#include "fmt/format.h"
+#include "modify.h"
+#include "output.h"
+#include "region.h"
+#include "variable.h"
 
+#include <cmath>
+#include <cstring>
 #include <map>
+#include <utility>
 
 using namespace LAMMPS_NS;
 
@@ -538,7 +535,7 @@ void Group::assign(int narg, char **arg)
 
 void Group::assign(const std::string &groupcmd)
 {
-  std::vector<std::string> args = utils::split_words(groupcmd);
+  auto args = utils::split_words(groupcmd);
   char **newarg = new char*[args.size()];
   int i=0;
   for (const auto &arg : args) {
diff --git a/src/group.h b/src/group.h
index b9a5c27140..39c446d119 100644
--- a/src/group.h
+++ b/src/group.h
@@ -15,8 +15,8 @@
 #define LMP_GROUP_H
 
 #include "pointers.h"
+
 #include <map>
-#include <string>
 
 namespace LAMMPS_NS {
 
diff --git a/src/image.cpp b/src/image.cpp
index 56d9bc301a..755be587d8 100644
--- a/src/image.cpp
+++ b/src/image.cpp
@@ -16,16 +16,16 @@
 ------------------------------------------------------------------------- */
 
 #include "image.h"
-#include <mpi.h>
-#include <cmath>
-#include <cctype>
-#include <cstring>
-#include "math_extra.h"
-#include "random_mars.h"
-#include "math_const.h"
+
 #include "error.h"
-#include "force.h"
+#include "math_const.h"
+#include "math_extra.h"
 #include "memory.h"
+#include "random_mars.h"
+
+#include <cctype>
+#include <cmath>
+#include <cstring>
 
 #ifdef LAMMPS_JPEG
 #include <jpeglib.h>
diff --git a/src/imbalance_group.cpp b/src/imbalance_group.cpp
index 72b1028791..b7be70dd25 100644
--- a/src/imbalance_group.cpp
+++ b/src/imbalance_group.cpp
@@ -12,12 +12,11 @@
 ------------------------------------------------------------------------- */
 
 #include "imbalance_group.h"
+
 #include "atom.h"
+#include "error.h"
 #include "force.h"
 #include "group.h"
-#include "error.h"
-#include <string>
-#include "fmt/format.h"
 
 using namespace LAMMPS_NS;
 
diff --git a/src/imbalance_neigh.cpp b/src/imbalance_neigh.cpp
index 0beb62bdb4..70d5580b9c 100644
--- a/src/imbalance_neigh.cpp
+++ b/src/imbalance_neigh.cpp
@@ -12,15 +12,13 @@
 ------------------------------------------------------------------------- */
 
 #include "imbalance_neigh.h"
-#include <mpi.h>
+
 #include "atom.h"
 #include "comm.h"
-#include "force.h"
-#include "neighbor.h"
-#include "neigh_request.h"
-#include "neigh_list.h"
 #include "error.h"
-#include "fmt/format.h"
+#include "neigh_list.h"
+#include "neigh_request.h"
+#include "neighbor.h"
 
 using namespace LAMMPS_NS;
 
diff --git a/src/imbalance_store.cpp b/src/imbalance_store.cpp
index 919d1f3f61..2661b57b25 100644
--- a/src/imbalance_store.cpp
+++ b/src/imbalance_store.cpp
@@ -12,10 +12,11 @@
 ------------------------------------------------------------------------- */
 
 #include "imbalance_store.h"
-#include <cstring>
+
 #include "atom.h"
 #include "error.h"
-#include "fmt/format.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/imbalance_time.cpp b/src/imbalance_time.cpp
index 99e549e90e..438728ef3e 100644
--- a/src/imbalance_time.cpp
+++ b/src/imbalance_time.cpp
@@ -12,12 +12,10 @@
 ------------------------------------------------------------------------- */
 
 #include "imbalance_time.h"
-#include <mpi.h>
+
 #include "atom.h"
-#include "force.h"
-#include "timer.h"
 #include "error.h"
-#include "fmt/format.h"
+#include "timer.h"
 
 using namespace LAMMPS_NS;
 
diff --git a/src/imbalance_var.cpp b/src/imbalance_var.cpp
index d1a76ed9f7..a2c940789e 100644
--- a/src/imbalance_var.cpp
+++ b/src/imbalance_var.cpp
@@ -12,15 +12,15 @@
 ------------------------------------------------------------------------- */
 
 #include "imbalance_var.h"
-#include <mpi.h>
-#include <cstring>
+
 #include "atom.h"
+#include "error.h"
 #include "group.h"
 #include "input.h"
-#include "variable.h"
 #include "memory.h"
-#include "error.h"
-#include "fmt/format.h"
+#include "variable.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/improper_zero.cpp b/src/improper_zero.cpp
index 11c9257ec9..3da38a890c 100644
--- a/src/improper_zero.cpp
+++ b/src/improper_zero.cpp
@@ -16,12 +16,12 @@
 ------------------------------------------------------------------------- */
 
 #include "improper_zero.h"
-#include <cstring>
-#include "atom.h"
-#include "force.h"
-#include "memory.h"
-#include "error.h"
 
+#include "atom.h"
+#include "error.h"
+#include "memory.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/info.cpp b/src/info.cpp
index fbe43442f0..79ba9f7a45 100644
--- a/src/info.cpp
+++ b/src/info.cpp
@@ -17,39 +17,37 @@
 ------------------------------------------------------------------------- */
 
 #include "info.h"
-#include <mpi.h>
-#include <cmath>
-#include <cstring>
-#include <cctype>
-#include <ctime>
-#include <map>
-#include <string>
+
 #include "accelerator_kokkos.h"
+#include "angle.h"
 #include "atom.h"
+#include "bond.h"
 #include "comm.h"
 #include "compute.h"
+#include "dihedral.h"
 #include "domain.h"
 #include "dump.h"
+#include "error.h"
 #include "fix.h"
 #include "force.h"
-#include "pair.h"
-#include "pair_hybrid.h"
-#include "bond.h"
-#include "angle.h"
-#include "dihedral.h"
-#include "improper.h"
 #include "group.h"
+#include "improper.h"
 #include "input.h"
 #include "modify.h"
 #include "neighbor.h"
 #include "output.h"
+#include "pair.h"
+#include "pair_hybrid.h"
 #include "region.h"
 #include "universe.h"
-#include "variable.h"
 #include "update.h"
-#include "error.h"
-#include "utils.h"
-#include "fmt/format.h"
+#include "variable.h"
+
+#include <cctype>
+#include <cmath>
+#include <cstring>
+#include <ctime>
+#include <map>
 
 #ifdef _WIN32
 #define PSAPI_VERSION 1
diff --git a/src/info.h b/src/info.h
index 5a379eaa78..65690ab28e 100644
--- a/src/info.h
+++ b/src/info.h
@@ -21,7 +21,7 @@ CommandStyle(info,Info)
 #define LMP_INFO_H
 
 #include "pointers.h"
-#include <string>
+
 #include <vector>
 
 namespace LAMMPS_NS {
diff --git a/src/input.cpp b/src/input.cpp
index c74232648c..84abaf141f 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -12,45 +12,44 @@
 ------------------------------------------------------------------------- */
 
 #include "input.h"
-#include <mpi.h>
+
+#include "accelerator_kokkos.h"
+#include "angle.h"
+#include "atom.h"
+#include "atom_vec.h"
+#include "bond.h"
+#include "comm.h"
+#include "comm_brick.h"
+#include "comm_tiled.h"
+#include "compute.h"
+#include "dihedral.h"
+#include "domain.h"
+#include "error.h"
+#include "fix.h"
+#include "force.h"
+#include "group.h"
+#include "improper.h"
+#include "kspace.h"
+#include "memory.h"
+#include "min.h"
+#include "modify.h"
+#include "neighbor.h"
+#include "output.h"
+#include "pair.h"
+#include "special.h"
+#include "style_command.h"
+#include "thermo.h"
+#include "timer.h"
+#include "universe.h"
+#include "update.h"
+#include "variable.h"
+
 #include <cstdlib>
 #include <cstring>
 #include <errno.h>
 #include <cctype>
-#include <unistd.h>
 #include <sys/stat.h>
-#include "style_command.h"
-#include "universe.h"
-#include "atom.h"
-#include "atom_vec.h"
-#include "comm.h"
-#include "comm_brick.h"
-#include "comm_tiled.h"
-#include "group.h"
-#include "domain.h"
-#include "output.h"
-#include "thermo.h"
-#include "force.h"
-#include "pair.h"
-#include "min.h"
-#include "modify.h"
-#include "compute.h"
-#include "fix.h"
-#include "bond.h"
-#include "angle.h"
-#include "dihedral.h"
-#include "improper.h"
-#include "kspace.h"
-#include "update.h"
-#include "neighbor.h"
-#include "special.h"
-#include "timer.h"
-#include "variable.h"
-#include "accelerator_kokkos.h"
-#include "error.h"
-#include "memory.h"
-#include "utils.h"
-#include "fmt/format.h"
+#include <unistd.h>
 
 #ifdef _WIN32
 #include <direct.h>
diff --git a/src/input.h b/src/input.h
index 48caa13fde..b8ffb276f9 100644
--- a/src/input.h
+++ b/src/input.h
@@ -15,8 +15,8 @@
 #define LMP_INPUT_H
 
 #include "pointers.h"
+
 #include <map>
-#include <string>
 
 namespace LAMMPS_NS {
 
diff --git a/src/irregular.cpp b/src/irregular.cpp
index 2213b37d55..f6de6947bd 100644
--- a/src/irregular.cpp
+++ b/src/irregular.cpp
@@ -12,15 +12,16 @@
 ------------------------------------------------------------------------- */
 
 #include "irregular.h"
-#include <mpi.h>
-#include <cstring>
+
 #include "atom.h"
 #include "atom_vec.h"
-#include "domain.h"
 #include "comm.h"
-#include "modify.h"
+#include "domain.h"
 #include "fix.h"
 #include "memory.h"
+#include "modify.h"
+
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/kspace.cpp b/src/kspace.cpp
index 2485db67b8..e51cc54c97 100644
--- a/src/kspace.cpp
+++ b/src/kspace.cpp
@@ -12,21 +12,19 @@
 ------------------------------------------------------------------------- */
 
 #include "kspace.h"
-#include <mpi.h>
-#include <cmath>
-#include <cstdlib>
-#include <cstring>
-#include <string>
+
 #include "atom.h"
-#include "comm.h"
-#include "force.h"
-#include "pair.h"
-#include "memory.h"
 #include "atom_masks.h"
-#include "error.h"
-#include "suffix.h"
+#include "comm.h"
 #include "domain.h"
-#include "fmt/format.h"
+#include "error.h"
+#include "force.h"
+#include "memory.h"
+#include "pair.h"
+#include "suffix.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/kspace_deprecated.cpp b/src/kspace_deprecated.cpp
index 5dc2b50e2b..16e9ff6abb 100644
--- a/src/kspace_deprecated.cpp
+++ b/src/kspace_deprecated.cpp
@@ -16,11 +16,10 @@
 ------------------------------------------------------------------------- */
 
 #include "kspace_deprecated.h"
-#include <string>
+
 #include "comm.h"
 #include "force.h"
 #include "error.h"
-#include "utils.h"
 
 using namespace LAMMPS_NS;
 
diff --git a/src/lammps.cpp b/src/lammps.cpp
index ded9d93167..b6c8450a4d 100644
--- a/src/lammps.cpp
+++ b/src/lammps.cpp
@@ -12,13 +12,7 @@
 ------------------------------------------------------------------------- */
 
 #include "lammps.h"
-#include <mpi.h>
-#include <cmath>
-#include <cstring>
-#include <cstdlib>
-#include <cctype>
-#include <map>
-#include <string>
+
 #include "style_angle.h"     // IWYU pragma: keep
 #include "style_atom.h"      // IWYU pragma: keep
 #include "style_bond.h"      // IWYU pragma: keep
@@ -54,8 +48,11 @@
 #include "version.h"
 #include "memory.h"
 #include "error.h"
-#include "utils.h"
-#include "fmt/format.h"
+
+#include <cctype>
+#include <cmath>
+#include <cstring>
+#include <map>
 
 #include "lmpinstalledpkgs.h"
 #include "lmpgitversion.h"