diff --git a/Mac/Python/macglue.c b/Mac/Python/macglue.c
index cbeeee71f4e..53f130f2735 100644
--- a/Mac/Python/macglue.c
+++ b/Mac/Python/macglue.c
@@ -123,6 +123,7 @@ char *macstrerror(int err)
 		HLock(h);
 		str = (char *)*h;
 		memcpy(buf, str+1, (unsigned char)str[0]);
+		buf[(unsigned char)str[0]] = '\0';
 		HUnlock(h);
 		ReleaseResource(h);
 	} else {