diff --git a/dir.c b/dir.c
index eecbfe2d96..311cd54273 100644
--- a/dir.c
+++ b/dir.c
@@ -504,7 +504,7 @@ static DIR *
 opendir_without_gvl(const char *path)
 {
     if (vm_initialized) {
-	union { const char *in; void *out; } u;
+	union { const void *in; void *out; } u;
 
 	u.in = path;