diff --git a/src/GPU/Install.sh b/src/GPU/Install.sh
index e84cc2b6f5..81cb0a73fa 100644
--- a/src/GPU/Install.sh
+++ b/src/GPU/Install.sh
@@ -104,6 +104,8 @@ elif (test $1 = 0) then
   rm -f ../pair_lj_class2_gpu.cpp
   rm -f ../pair_lj_class2_coul_long_gpu.cpp
   rm -f ../pair_lj_charmm_coul_long_gpu.cpp
+  rm -f ../pair_lj_sdk_gpu.cpp
+  rm -f ../pair_lj_sdk_coul_long_gpu.cpp
   rm -f ../pair_coul_long_gpu.cpp
 
   rm -f ../fix_gpu.cpp
@@ -120,6 +122,8 @@ elif (test $1 = 0) then
   rm -f ../pair_lj_class2_gpu.h
   rm -f ../pair_lj_class2_coul_long_gpu.h
   rm -f ../pair_lj_charmm_coul_long_gpu.h
+  rm -f ../pair_lj_sdk_gpu.h
+  rm -f ../pair_lj_sdk_coul_long_gpu.h
   rm -f ../pair_coul_long_gpu.h
 
   rm -f ../fix_gpu.h
diff --git a/src/GPU/Package.sh b/src/GPU/Package.sh
index cb7213c2bc..89049b8b8b 100644
--- a/src/GPU/Package.sh
+++ b/src/GPU/Package.sh
@@ -21,16 +21,16 @@ for file in *.cpp *.h; do
   if (test $file = pair_coul_long_gpu.h -a ! -e ../pair_coul_long.cpp) then
     continue
   fi
-  if (test $file = pair_cg_cmm_gpu.cpp -a ! -e ../pair_cg_cmm.cpp) then
+  if (test $file = pair_lj_sdk_gpu.cpp -a ! -e ../pair_lj_sdk.cpp) then
     continue
   fi
-  if (test $file = pair_cg_cmm_gpu.h -a ! -e ../pair_cg_cmm.cpp) then
+  if (test $file = pair_lj_sdk_gpu.h -a ! -e ../pair_lj_sdk.cpp) then
     continue
   fi
-  if (test $file = pair_cg_cmm_coul_long_gpu.cpp -a ! -e ../pair_cg_cmm_coul_long.cpp) then
+  if (test $file = pair_lj_sdk_coul_long_gpu.cpp -a ! -e ../pair_lj_sdk_coul_long.cpp) then
     continue
   fi
-  if (test $file = pair_cg_cmm_coul_long_gpu.h -a ! -e ../pair_cg_cmm_coul_long.cpp) then
+  if (test $file = pair_lj_sdk_coul_long_gpu.h -a ! -e ../pair_lj_sdk_coul_long.cpp) then
     continue
   fi
 
diff --git a/src/GPU/gpu_extra.h b/src/GPU/gpu_extra.h
index d03beaf21a..abae643e54 100644
--- a/src/GPU/gpu_extra.h
+++ b/src/GPU/gpu_extra.h
@@ -1,4 +1,4 @@
-/* ----------------------------------------------------------------------
+/* -*- c++ -*- ----------------------------------------------------------
    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
    http://lammps.sandia.gov, Sandia National Laboratories
    Steve Plimpton, sjplimp@sandia.gov
@@ -18,6 +18,7 @@
 #ifndef LMP_GPU_EXTRA_H
 #define LMP_GPU_EXTRA_H
 
+#include "modify.h"
 #include "error.h"
 
 namespace GPU_EXTRA {
@@ -47,8 +48,13 @@ namespace GPU_EXTRA {
       else
 	error->all(FLERR,"Unknown error in GPU library");
     }
-  }
+  };
 
+  inline void gpu_ready(LAMMPS_NS::Modify *modify, LAMMPS_NS::Error *error) {
+    int ifix = modify->find_fix("package_gpu");
+    if (ifix < 0)
+      error->all(FLERR,"The 'package gpu' command is required for /gpu styles");
+  };
 }
 
 #endif
diff --git a/src/GPU/pair_coul_long_gpu.cpp b/src/GPU/pair_coul_long_gpu.cpp
index 5d311a34f4..6d7981d2e6 100644
--- a/src/GPU/pair_coul_long_gpu.cpp
+++ b/src/GPU/pair_coul_long_gpu.cpp
@@ -77,6 +77,7 @@ PairCoulLongGPU::PairCoulLongGPU(LAMMPS *lmp) :
 {
   respa_enable = 0;
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_gayberne_gpu.cpp b/src/GPU/pair_gayberne_gpu.cpp
index ce65ca2c83..18c9f6356d 100644
--- a/src/GPU/pair_gayberne_gpu.cpp
+++ b/src/GPU/pair_gayberne_gpu.cpp
@@ -77,6 +77,7 @@ PairGayBerneGPU::PairGayBerneGPU(LAMMPS *lmp) : PairGayBerne(lmp),
     error->all(FLERR,"Pair gayberne requires atom style ellipsoid");
   quat_nmax = 0;
   quat = NULL;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj96_cut_gpu.cpp b/src/GPU/pair_lj96_cut_gpu.cpp
index b678d842e9..b67bdb28dd 100644
--- a/src/GPU/pair_lj96_cut_gpu.cpp
+++ b/src/GPU/pair_lj96_cut_gpu.cpp
@@ -66,6 +66,7 @@ PairLJ96CutGPU::PairLJ96CutGPU(LAMMPS *lmp) : PairLJ96Cut(lmp), gpu_mode(GPU_FOR
 {
   respa_enable = 0;
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj_charmm_coul_long_gpu.cpp b/src/GPU/pair_lj_charmm_coul_long_gpu.cpp
index 488d4195f4..f654212abe 100644
--- a/src/GPU/pair_lj_charmm_coul_long_gpu.cpp
+++ b/src/GPU/pair_lj_charmm_coul_long_gpu.cpp
@@ -83,6 +83,7 @@ PairLJCharmmCoulLongGPU::PairLJCharmmCoulLongGPU(LAMMPS *lmp) :
 {
   respa_enable = 0;
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj_class2_coul_long_gpu.cpp b/src/GPU/pair_lj_class2_coul_long_gpu.cpp
index adaee7ab6a..289ddfa9ca 100644
--- a/src/GPU/pair_lj_class2_coul_long_gpu.cpp
+++ b/src/GPU/pair_lj_class2_coul_long_gpu.cpp
@@ -80,6 +80,7 @@ PairLJClass2CoulLongGPU::PairLJClass2CoulLongGPU(LAMMPS *lmp) :
   PairLJClass2CoulLong(lmp), gpu_mode(GPU_FORCE)
 {
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj_class2_gpu.cpp b/src/GPU/pair_lj_class2_gpu.cpp
index 65dcea9040..66395f28d3 100644
--- a/src/GPU/pair_lj_class2_gpu.cpp
+++ b/src/GPU/pair_lj_class2_gpu.cpp
@@ -65,6 +65,7 @@ using namespace LAMMPS_NS;
 PairLJClass2GPU::PairLJClass2GPU(LAMMPS *lmp) : PairLJClass2(lmp), gpu_mode(GPU_FORCE)
 {
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj_cut_coul_cut_gpu.cpp b/src/GPU/pair_lj_cut_coul_cut_gpu.cpp
index 33a49f20f3..8311b6d732 100644
--- a/src/GPU/pair_lj_cut_coul_cut_gpu.cpp
+++ b/src/GPU/pair_lj_cut_coul_cut_gpu.cpp
@@ -71,6 +71,7 @@ PairLJCutCoulCutGPU::PairLJCutCoulCutGPU(LAMMPS *lmp) : PairLJCutCoulCut(lmp), g
 {
   respa_enable = 0;
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj_cut_coul_long_gpu.cpp b/src/GPU/pair_lj_cut_coul_long_gpu.cpp
index 077e3eff71..7f4a09f540 100644
--- a/src/GPU/pair_lj_cut_coul_long_gpu.cpp
+++ b/src/GPU/pair_lj_cut_coul_long_gpu.cpp
@@ -81,6 +81,7 @@ PairLJCutCoulLongGPU::PairLJCutCoulLongGPU(LAMMPS *lmp) :
 {
   respa_enable = 0;
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj_cut_gpu.cpp b/src/GPU/pair_lj_cut_gpu.cpp
index 2c0c2f3f1d..19c3df9227 100644
--- a/src/GPU/pair_lj_cut_gpu.cpp
+++ b/src/GPU/pair_lj_cut_gpu.cpp
@@ -66,6 +66,7 @@ PairLJCutGPU::PairLJCutGPU(LAMMPS *lmp) : PairLJCut(lmp), gpu_mode(GPU_FORCE)
 {
   respa_enable = 0;
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_lj_expand_gpu.cpp b/src/GPU/pair_lj_expand_gpu.cpp
index 40c7ea1a37..8e208489cb 100644
--- a/src/GPU/pair_lj_expand_gpu.cpp
+++ b/src/GPU/pair_lj_expand_gpu.cpp
@@ -67,6 +67,7 @@ PairLJExpandGPU::PairLJExpandGPU(LAMMPS *lmp) : PairLJExpand(lmp), gpu_mode(GPU_
 {
   respa_enable = 0;
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_morse_gpu.cpp b/src/GPU/pair_morse_gpu.cpp
index 0867e5a998..ef470f925a 100644
--- a/src/GPU/pair_morse_gpu.cpp
+++ b/src/GPU/pair_morse_gpu.cpp
@@ -65,6 +65,7 @@ using namespace LAMMPS_NS;
 PairMorseGPU::PairMorseGPU(LAMMPS *lmp) : PairMorse(lmp), gpu_mode(GPU_FORCE)
 {
   cpu_time = 0.0;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pair_resquared_gpu.cpp b/src/GPU/pair_resquared_gpu.cpp
index 4057f45c5e..566712ec46 100644
--- a/src/GPU/pair_resquared_gpu.cpp
+++ b/src/GPU/pair_resquared_gpu.cpp
@@ -76,6 +76,7 @@ PairRESquaredGPU::PairRESquaredGPU(LAMMPS *lmp) : PairRESquared(lmp),
     error->all(FLERR,"Pair gayberne requires atom style ellipsoid");
   quat_nmax = 0;
   quat = NULL;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/GPU/pppm_gpu.cpp b/src/GPU/pppm_gpu.cpp
index 9dc7362867..437f9c115f 100644
--- a/src/GPU/pppm_gpu.cpp
+++ b/src/GPU/pppm_gpu.cpp
@@ -84,6 +84,7 @@ PPPMGPU::PPPMGPU(LAMMPS *lmp, int narg, char **arg) : PPPM(lmp, narg, arg)
   if (narg != 1) error->all(FLERR,"Illegal kspace_style pppm/gpu command");
 
   density_brick_gpu = vd_brick = NULL;
+  GPU_EXTRA::gpu_ready(lmp->modify, lmp->error); 
 }
 
 /* ----------------------------------------------------------------------