diff --git a/tools/lint/common.c b/tools/lint/common.c
index 16e05d1..d2b4f5e 100644
--- a/tools/lint/common.c
+++ b/tools/lint/common.c
@@ -426,7 +426,7 @@
 int
 evaluate_xpath(const struct lyd_node *tree, const char *xpath)
 {
-    struct ly_set *set;
+    struct ly_set *set = NULL;
 
     if (lyd_find_xpath(tree, xpath, &set)) {
         return -1;
@@ -463,9 +463,9 @@
         struct cmdline_file *operational_f, struct ly_set *inputs, struct ly_set *request_paths, struct ly_set *requests,
         struct ly_set *xpaths)
 {
-    LY_ERR ret;
+    LY_ERR ret = LY_SUCCESS;
     struct lyd_node *tree = NULL, *merged_tree = NULL;
-    struct lyd_node *operational;
+    struct lyd_node *operational = NULL;
 
     /* additional operational datastore */
     if (operational_f && operational_f->in) {
@@ -524,6 +524,9 @@
         case LYD_VALIDATE_OP_NOTIF:
             ret = lyd_parse_notif(ctx, input_f->in, input_f->format, &tree, NULL);
             break;
+        default:
+            YLMSG_E("Internal error (%s:%d).\n", __FILE__, __LINE__);
+            goto cleanup;
         }
 
         if (ret) {