diff --git a/h_malloc.c b/h_malloc.c
index 7d659af..5ea336f 100644
--- a/h_malloc.c
+++ b/h_malloc.c
@@ -1087,7 +1087,7 @@ EXPORT void *h_calloc(size_t nmemb, size_t size) {
     total_size = adjust_size_for_canaries(total_size);
     void *p = allocate(total_size);
     thread_seal_metadata();
-    if (!ZERO_ON_FREE && likely(p != NULL) && size && size <= max_slab_size_class) {
+    if (!ZERO_ON_FREE && likely(p != NULL) && total_size && total_size <= max_slab_size_class) {
         memset(p, 0, total_size - canary_size);
     }
     return p;