diff --git a/libtcc.c b/libtcc.c
index ffd0f376..36986328 100644
--- a/libtcc.c
+++ b/libtcc.c
@@ -245,7 +245,8 @@ PUB_FUNC void *tcc_mallocz(unsigned long size)
 {
     void *ptr;
     ptr = tcc_malloc(size);
-    memset(ptr, 0, size);
+    if (size)
+        memset(ptr, 0, size);
     return ptr;
 }