diff --git a/tests/Issues/ImportFullyQualifiedIdentifierDocblock/Source/AddFullyQualifiedIdentifierDocblockRector.php b/tests/Issues/ImportFullyQualifiedIdentifierDocblock/Source/AddFullyQualifiedIdentifierDocblockRector.php
index 5657dd4d7c8..0f040cb9e73 100644
--- a/tests/Issues/ImportFullyQualifiedIdentifierDocblock/Source/AddFullyQualifiedIdentifierDocblockRector.php
+++ b/tests/Issues/ImportFullyQualifiedIdentifierDocblock/Source/AddFullyQualifiedIdentifierDocblockRector.php
@@ -36,6 +36,12 @@ public function getNodeTypes(): array
     public function refactor(Node $node)
     {
         $phpDocInfo = $this->phpDocInfoFactory->createFromNodeOrEmpty($node);
+
+        // make rule idempotent, do not add if already present
+        if ($phpDocInfo->getVarTagValueNode() instanceof VarTagValueNode) {
+            return null;
+        }
+
         $varTagValueNode = new VarTagValueNode(new FullyQualifiedIdentifierTypeNode('DateTime'), '', '');
 
         $phpDocInfo->addTagValueNode($varTagValueNode);