diff --git a/src/legacy.c b/src/legacy.c
index f5954df5..f8a159f5 100644
--- a/src/legacy.c
+++ b/src/legacy.c
@@ -487,7 +487,9 @@ ssh_string publickey_from_file(ssh_session session, const char *filename,
         return NULL;
     }
 
-    *type = key->type;
+    if (type) {
+        *type = key->type;
+    }
     ssh_key_free(key);
 
     return key_str;