diff --git a/src/BulletCollision/BroadphaseCollision/btDbvt.h b/src/BulletCollision/BroadphaseCollision/btDbvt.h
index e05e1de27..db4e482f2 100644
--- a/src/BulletCollision/BroadphaseCollision/btDbvt.h
+++ b/src/BulletCollision/BroadphaseCollision/btDbvt.h
@@ -1196,23 +1196,32 @@ inline void		btDbvt::collideOCL(	const btDbvtNode* root,
 							
 							//void * memmove ( void * destination, const void * source, size_t num );
 							
-//#if DBVT_USE_MEMMOVE
-//							memmove(&stack[j],&stack[j-1],sizeof(int)*(stack.size()-j-1));
-//#else
-							for(int k=stack.size()-1;k>j;--k) 
-							{
+#if DBVT_USE_MEMMOVE
+                     {
+                     int num_items_to_move = stack.size()-1-j;
+                     if(num_items_to_move > 0)
+                        memmove(&stack[j+1],&stack[j],sizeof(int)*num_items_to_move);
+                     }
+#else
+                     for(int k=stack.size()-1;k>j;--k) {
 								stack[k]=stack[k-1];
-							}
-//#endif
+                     }
+#endif
 							stack[j]=allocate(ifree,stock,nes[q]);
 							/* Insert 1	*/ 
 							j=nearest(&stack[0],&stock[0],nes[1-q].value,j,stack.size());
 							stack.push_back(0);
-//#if DBVT_USE_MEMMOVE
-//							memmove(&stack[j],&stack[j-1],sizeof(int)*(stack.size()-j-1));
-//#else
-							for(int k=stack.size()-1;k>j;--k) stack[k]=stack[k-1];
-//#endif
+#if DBVT_USE_MEMMOVE
+                     {
+                     int num_items_to_move = stack.size()-1-j;
+                     if(num_items_to_move > 0)
+                        memmove(&stack[j+1],&stack[j],sizeof(int)*num_items_to_move);
+                     }
+#else
+                     for(int k=stack.size()-1;k>j;--k) {
+                        stack[k]=stack[k-1];
+                     }
+#endif
 							stack[j]=allocate(ifree,stock,nes[1-q]);
 						}
 						else