diff --git a/src/USER-OMP/ewald_omp.cpp b/src/USER-OMP/ewald_omp.cpp
index ec8d708da2..d5480d2a9f 100644
--- a/src/USER-OMP/ewald_omp.cpp
+++ b/src/USER-OMP/ewald_omp.cpp
@@ -15,18 +15,18 @@
    Contributing authors: Roy Pollock (LLNL), Paul Crozier (SNL)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "ewald_omp.h"
-#include <mpi.h>
-#include <cmath>
+
 #include "atom.h"
 #include "comm.h"
 #include "force.h"
-#include "memory.h"
-#include "timer.h"
 #include "math_const.h"
-
+#include "memory.h"
 #include "suffix.h"
+
+#include <cmath>
+
+#include "omp_compat.h"
 using namespace LAMMPS_NS;
 using namespace MathConst;
 
diff --git a/src/USER-OMP/improper_fourier_omp.cpp b/src/USER-OMP/improper_fourier_omp.cpp
index 0671bdc375..3763465e79 100644
--- a/src/USER-OMP/improper_fourier_omp.cpp
+++ b/src/USER-OMP/improper_fourier_omp.cpp
@@ -15,18 +15,20 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
-#include <cmath>
 #include "improper_fourier_omp.h"
+
 #include "atom.h"
 #include "comm.h"
-#include "neighbor.h"
-#include "timer.h"
-#include "force.h"
-#include "update.h"
 #include "error.h"
-
+#include "force.h"
+#include "neighbor.h"
 #include "suffix.h"
+#include "timer.h"
+#include "update.h"
+
+#include <cmath>
+
+#include "omp_compat.h"
 using namespace LAMMPS_NS;
 
 #define TOLERANCE 0.05
diff --git a/src/USER-OMP/improper_ring_omp.cpp b/src/USER-OMP/improper_ring_omp.cpp
index 4ba67aab70..51ea5e5198 100644
--- a/src/USER-OMP/improper_ring_omp.cpp
+++ b/src/USER-OMP/improper_ring_omp.cpp
@@ -15,17 +15,18 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "improper_ring_omp.h"
-#include <cmath>
+
 #include "atom.h"
 #include "comm.h"
-#include "neighbor.h"
-#include "timer.h"
 #include "force.h"
 #include "math_special.h"
-
+#include "neighbor.h"
 #include "suffix.h"
+
+#include <cmath>
+
+#include "omp_compat.h"
 using namespace LAMMPS_NS;
 using namespace MathSpecial;
 
diff --git a/src/USER-OMP/msm_cg_omp.cpp b/src/USER-OMP/msm_cg_omp.cpp
index 524850eb63..93904fd8f8 100644
--- a/src/USER-OMP/msm_cg_omp.cpp
+++ b/src/USER-OMP/msm_cg_omp.cpp
@@ -16,24 +16,21 @@
    Original MSM class by: Paul Crozier, Stan Moore, Stephen Bond, (all SNL)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "msm_cg_omp.h"
-#include <mpi.h>
-#include <cmath>
-#include <cstdio>
-#include <cstring>
 
 #include "atom.h"
-#include "gridcomm.h"
 #include "domain.h"
 #include "error.h"
 #include "force.h"
-#include "neighbor.h"
+#include "gridcomm.h"
 #include "memory.h"
+#include "neighbor.h"
 #include "thr_omp.h"
-#include "timer.h"
-#include "utils.h"
-#include "fmt/format.h"
+
+#include <cmath>
+#include <cstring>
+
+#include "omp_compat.h"
 
 using namespace LAMMPS_NS;
 
diff --git a/src/USER-OMP/msm_omp.cpp b/src/USER-OMP/msm_omp.cpp
index 2689226725..783ebb40f1 100644
--- a/src/USER-OMP/msm_omp.cpp
+++ b/src/USER-OMP/msm_omp.cpp
@@ -15,14 +15,15 @@
    Contributing authors: Axel Kohlmeyer (Temple U), Stan Moore (SNL)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "msm_omp.h"
-#include <cstring>
+
 #include "comm.h"
 #include "domain.h"
 #include "error.h"
-#include "timer.h"
 
+#include <cstring>
+
+#include "omp_compat.h"
 #if defined(_OPENMP)
 #include <omp.h>
 #endif
diff --git a/src/USER-OMP/pppm_cg_omp.cpp b/src/USER-OMP/pppm_cg_omp.cpp
index 31098d2675..86997713ef 100644
--- a/src/USER-OMP/pppm_cg_omp.cpp
+++ b/src/USER-OMP/pppm_cg_omp.cpp
@@ -15,22 +15,24 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "pppm_cg_omp.h"
-#include <mpi.h>
-#include <cstring>
-#include <cmath>
+
 #include "atom.h"
 #include "comm.h"
 #include "domain.h"
 #include "force.h"
 #include "math_const.h"
 #include "math_special.h"
-#include "timer.h"
+#include "suffix.h"
+
+#include <cmath>
+#include <cstring>
+
+#include "omp_compat.h"
 #if defined(_OPENMP)
 #include <omp.h>
 #endif
-#include "suffix.h"
+
 using namespace LAMMPS_NS;
 using namespace MathConst;
 using namespace MathSpecial;
diff --git a/src/USER-OMP/pppm_disp_tip4p_omp.cpp b/src/USER-OMP/pppm_disp_tip4p_omp.cpp
index 7da4257e07..93b7a87a61 100644
--- a/src/USER-OMP/pppm_disp_tip4p_omp.cpp
+++ b/src/USER-OMP/pppm_disp_tip4p_omp.cpp
@@ -15,21 +15,24 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "pppm_disp_tip4p_omp.h"
-#include <mpi.h>
-#include <cstring>
-#include <cmath>
+
 #include "atom.h"
 #include "comm.h"
 #include "domain.h"
 #include "error.h"
 #include "force.h"
 #include "math_const.h"
+#include "suffix.h"
+
+#include <cstring>
+#include <cmath>
+
+#include "omp_compat.h"
 #if defined(_OPENMP)
 #include <omp.h>
 #endif
-#include "suffix.h"
+
 using namespace LAMMPS_NS;
 using namespace MathConst;
 
diff --git a/src/USER-OMP/pppm_omp.cpp b/src/USER-OMP/pppm_omp.cpp
index e3e46f4de0..7065588526 100644
--- a/src/USER-OMP/pppm_omp.cpp
+++ b/src/USER-OMP/pppm_omp.cpp
@@ -15,19 +15,19 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "pppm_omp.h"
-#include <mpi.h>
-#include <cstring>
-#include <cmath>
+
 #include "atom.h"
 #include "comm.h"
 #include "domain.h"
 #include "force.h"
 #include "math_const.h"
 #include "math_special.h"
-#include "timer.h"
 
+#include <cmath>
+#include <cstring>
+
+#include "omp_compat.h"
 #if defined(_OPENMP)
 #include <omp.h>
 #endif
diff --git a/src/USER-OMP/pppm_tip4p_omp.cpp b/src/USER-OMP/pppm_tip4p_omp.cpp
index 8bd9805f01..936f3cf31c 100644
--- a/src/USER-OMP/pppm_tip4p_omp.cpp
+++ b/src/USER-OMP/pppm_tip4p_omp.cpp
@@ -15,11 +15,8 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "pppm_tip4p_omp.h"
-#include <mpi.h>
-#include <cstring>
-#include <cmath>
+
 #include "atom.h"
 #include "comm.h"
 #include "domain.h"
@@ -27,12 +24,16 @@
 #include "force.h"
 #include "math_const.h"
 #include "math_special.h"
-#include "timer.h"
+#include "suffix.h"
+
+#include <cstring>
+#include <cmath>
+
+#include "omp_compat.h"
 #if defined(_OPENMP)
 #include <omp.h>
 #endif
 
-#include "suffix.h"
 using namespace LAMMPS_NS;
 using namespace MathConst;
 using namespace MathSpecial;
diff --git a/src/USER-OMP/respa_omp.cpp b/src/USER-OMP/respa_omp.cpp
index b5e5293aa4..b8d0af5c86 100644
--- a/src/USER-OMP/respa_omp.cpp
+++ b/src/USER-OMP/respa_omp.cpp
@@ -15,25 +15,25 @@
    Contributing authors: Mark Stevens (SNL), Paul Crozier (SNL)
 ------------------------------------------------------------------------- */
 
-#include "omp_compat.h"
 #include "respa_omp.h"
-#include "neighbor.h"
-#include "comm.h"
-#include "atom.h"
-#include "domain.h"
-#include "force.h"
-#include "pair.h"
-#include "bond.h"
+
 #include "angle.h"
+#include "atom.h"
+#include "bond.h"
+#include "comm.h"
 #include "dihedral.h"
+#include "domain.h"
+#include "error.h"
+#include "force.h"
 #include "improper.h"
 #include "kspace.h"
-#include "output.h"
-#include "update.h"
 #include "modify.h"
-#include "error.h"
-#include "timer.h"
+#include "neighbor.h"
+#include "output.h"
+#include "pair.h"
+#include "update.h"
 
+#include "omp_compat.h"
 #if defined(_OPENMP)
 #include <omp.h>
 #endif
diff --git a/src/USER-OMP/thr_data.h b/src/USER-OMP/thr_data.h
index 4853d6dbbf..4b87357101 100644
--- a/src/USER-OMP/thr_data.h
+++ b/src/USER-OMP/thr_data.h
@@ -18,7 +18,7 @@
 #ifndef LMP_THR_DATA_H
 #define LMP_THR_DATA_H
 
-#include "timer.h"
+#include "timer.h"    // IWYU pragma: export
 
 namespace LAMMPS_NS {