diff --git a/src/KOKKOS/pppm_kokkos.cpp b/src/KOKKOS/pppm_kokkos.cpp
index c59bd89e51303784efef00d44be83c84b3960a7c..3ad7334d2f55c982e54e410357c7f3deb445d534 100644
--- a/src/KOKKOS/pppm_kokkos.cpp
+++ b/src/KOKKOS/pppm_kokkos.cpp
@@ -3158,7 +3158,7 @@ double PPPMKokkos<DeviceType>::memory_usage()
   if (peratom_allocate_flag)
     bytes += 6 * nbrick * sizeof(FFT_SCALAR);
 
-  bytes += cg->memory_usage();
+  if (cg) bytes += cg->memory_usage();
 
   return bytes;
 }
diff --git a/src/KSPACE/pppm.cpp b/src/KSPACE/pppm.cpp
index 156e867f348622b17976c288466d2065df1b4c46..80328a2d6fbc6796b62873acf003124b98d6efad 100644
--- a/src/KSPACE/pppm.cpp
+++ b/src/KSPACE/pppm.cpp
@@ -3085,7 +3085,7 @@ double PPPM::memory_usage()
     bytes += 2 * nfft_both * sizeof(FFT_SCALAR);;
   }
 
-  bytes += cg->memory_usage();
+  if (cg) bytes += cg->memory_usage();
 
   return bytes;
 }
diff --git a/src/KSPACE/pppm_disp.cpp b/src/KSPACE/pppm_disp.cpp
index 315bf16e4ddd66948457c7d1ed14d7569fdbd8f0..5d6c2042beec5c318f6a713642e49eb30b9f251b 100644
--- a/src/KSPACE/pppm_disp.cpp
+++ b/src/KSPACE/pppm_disp.cpp
@@ -8240,7 +8240,7 @@ double PPPMDisp::memory_usage()
     bytes += 6 * nfft_both * sizeof(double);      // vg
     bytes += nfft_both * sizeof(double);          // greensfn
     bytes += nfft_both * 3 * sizeof(FFT_SCALAR);    // density_FFT, work1, work2
-    bytes += cg->memory_usage();
+    if (cg) bytes += cg->memory_usage();
   }
 
   if (function[1] + function[2] + function[3]) {
@@ -8250,7 +8250,7 @@ double PPPMDisp::memory_usage()
     bytes += 6 * nfft_both_6 * sizeof(double);      // vg
     bytes += nfft_both_6 * sizeof(double);          // greensfn
     bytes += nfft_both_6 * (mixing + 2) * sizeof(FFT_SCALAR);    // density_FFT, work1, work2
-    bytes += cg_6->memory_usage();
+    if (cg_6) bytes += cg_6->memory_usage();
   }
   return bytes;
 }