--- a/p11-kit/modules.c
+++ b/p11-kit/modules.c
@@ -263,9 +263,14 @@
 	assert (filename);
 
 	len = snprintf (NULL, 0, "%s/%s", dir, filename) + 1;
-	if (len <= 0 || len > PATH_MAX)
+	if (len <= 0)
 		return NULL;
 
+#ifdef PATH_MAX
+	if (len > PATH_MAX)
+		return NULL;
+#endif
+
 	if (!(path = malloc (len)))
 		return NULL;