1 files changed, 6 insertions, 3 deletions
diff --git a/gc.c b/gc.c
index 6ce83469e6..5aac9738e3 100644
--- a/gc.c
+++ b/gc.c
@@ -866,8 +866,10 @@ vm_xfree(rb_objspace_t *objspace, void *ptr)
     size_t size;
     ptr = ((size_t *)ptr) - 1;
     size = ((size_t*)ptr)[0];
-    objspace->malloc_params.allocated_size -= size;
-    objspace->malloc_params.allocations--;
+    if (size) {
+	objspace->malloc_params.allocated_size -= size;
+	objspace->malloc_params.allocations--;
+    }
 #endif
 
     free(ptr);
@@ -950,7 +952,8 @@ ruby_mimmalloc(size_t size)
 #endif
     mem = malloc(size);
 #if CALC_EXACT_MALLOC_SIZE
-    ((size_t *)mem)[0] = size;
+    /* set 0 for consistency of allocated_size/allocations */
+    ((size_t *)mem)[0] = 0;
     mem = (size_t *)mem + 1;
 #endif
     return mem;