diff --git a/src/main.c b/src/main.c
index 9a19d277..8b0b4a26 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1323,7 +1323,7 @@ static int _tf_run_task(const tf_run_args_t* args, int index)
 	const char* script = args->script;
 	if (!script && cwd)
 	{
-		size_t script_size = strlen(cwd) + strlen("/core/core.js") + 1;
+		size_t script_size = (cwd ? strlen(cwd) : 0) + strlen("/core/core.js") + 1;
 		char* script_buffer = alloca(script_size);
 		snprintf(script_buffer, script_size, "%s/core/core.js", cwd);
 		script = script_buffer;