diff --git a/ggml.c b/ggml.c
index adb387100..4a0ec4c44 100644
--- a/ggml.c
+++ b/ggml.c
@@ -132,7 +132,7 @@ void ggml_print_backtrace(void) {
             "-ex", "bt -frame-info source-and-location",
             "-ex", "detach",
             "-ex", "quit",
-            NULL);
+            (char *) NULL);
     } else {
         waitpid(pid, NULL, 0);
     }