1 files changed, 4 insertions, 1 deletions
diff --git a/searchlib/src/tests/attribute/attribute_operation/attribute_operation_test.cpp b/searchlib/src/tests/attribute/attribute_operation/attribute_operation_test.cpp
index a57469e2bd1..baecb54fbec 100644
--- a/searchlib/src/tests/attribute/attribute_operation/attribute_operation_test.cpp
+++ b/searchlib/src/tests/attribute/attribute_operation/attribute_operation_test.cpp
@@ -47,15 +47,18 @@ TEST("test illegal operations on float attribute") {
 AttributeVector::SP
 createAttribute(BasicType basicType, const vespalib::string &fieldName, bool fastSearch = false, bool immutable = false)
 {
+    constexpr size_t NUM_DOCS = 20;
     Config cfg(basicType, CollectionType::SINGLE);
     cfg.setMutable(!immutable)
        .setFastSearch(fastSearch);
     auto av = search::AttributeFactory::createAttribute(fieldName, cfg);
-    while (20 >= av->getNumDocs()) {
+    while (NUM_DOCS >= av->getNumDocs()) {
         AttributeVector::DocId checkDocId(0u);
         ASSERT_TRUE(av->addDoc(checkDocId));
+        ASSERT_EQUAL(immutable, av->isUndefined(checkDocId));
     }
     av->commit();
+    ASSERT_EQUAL(immutable, av->isUndefined(NUM_DOCS/2));
     return av;
 }