diff --git a/src/KSPACE/ewald_disp.cpp b/src/KSPACE/ewald_disp.cpp
index afbb57f1f1..a8a5bc6d1f 100644
--- a/src/KSPACE/ewald_disp.cpp
+++ b/src/KSPACE/ewald_disp.cpp
@@ -408,8 +408,15 @@ void EwaldDisp::allocate_peratom()
 
 void EwaldDisp::deallocate_peratom()                        // free memory
 {
-  memory->destroy(energy_self_peratom);
-  memory->destroy(virial_self_peratom);
+  if (energy_self_peratom) {
+    memory->destroy(energy_self_peratom);
+    energy_self_peratom = NULL;
+  }
+
+  if (virial_self_peratom) {
+    memory->destroy(virial_self_peratom);
+    virial_self_peratom = NULL;
+  }
 }