diff --git a/lib/allocator/AlignedAllocator.h b/lib/allocator/AlignedAllocator.h
index 3b27aec9..b0f7e206 100644
--- a/lib/allocator/AlignedAllocator.h
+++ b/lib/allocator/AlignedAllocator.h
@@ -277,7 +277,9 @@ public:
     uint8_t *cp = (uint8_t *)ptr;
     if ( ptr ) { 
     // One touch per 4k page, static OMP loop to catch same loop order
+#ifdef GRID_OMP
 #pragma omp parallel for schedule(static)
+#endif
       for(size_type n=0;n<bytes;n+=4096){
 	cp[n]=0;
       }