diff --git a/src/tree_data.c b/src/tree_data.c
index 963f6b7..4f5f97a 100644
--- a/src/tree_data.c
+++ b/src/tree_data.c
@@ -2830,8 +2830,8 @@
         LOGERR(LYD_CTX(sibling), LY_EINVAL, "Can be used only for user-ordered nodes.");
         return LY_EINVAL;
     }
-    if (lysc_is_key(sibling->schema)) {
-        LOGERR(LYD_CTX(sibling), LY_EINVAL, "Cannot insert before keys.");
+    if (node->schema && sibling->schema && (node->schema != sibling->schema)) {
+        LOGERR(LYD_CTX(sibling), LY_EINVAL, "Cannot insert before a different schema node instance.");
         return LY_EINVAL;
     }
 
@@ -2854,8 +2854,8 @@
         LOGERR(LYD_CTX(sibling), LY_EINVAL, "Can be used only for user-ordered nodes.");
         return LY_EINVAL;
     }
-    if (sibling->next && lysc_is_key(sibling->next->schema)) {
-        LOGERR(LYD_CTX(sibling), LY_EINVAL, "Cannot insert before keys.");
+    if (node->schema && sibling->schema && (node->schema != sibling->schema)) {
+        LOGERR(LYD_CTX(sibling), LY_EINVAL, "Cannot insert after a different schema node instance.");
         return LY_EINVAL;
     }