diff --git a/includes/Hooks/ParserHooks.php b/includes/Hooks/ParserHooks.php
index 0ac0d804c..541e04f4b 100644
--- a/includes/Hooks/ParserHooks.php
+++ b/includes/Hooks/ParserHooks.php
@@ -86,6 +86,12 @@ class ParserHooks implements
 	 * @inheritDoc
 	 */
 	public function onParserOutputPostCacheTransform( $parserOutput, &$text, &$options ): void {
+		if ( $parserOutput->getExtensionData( 'DiscussionTools-tocInfo' ) !== null ) {
+			// Since getText() could be called multiple times, return if we have
+			// already processed this ParserOutput object
+			return;
+		}
+
 		// NOTE: This is a temporary proxy for 'isPreview' flag in ParserOptions.
 		// It is not clear whether 'editsectionEditLinks' is disabled only for previews.
 		$isPreview = empty( $options['enableSectionEditLinks'] );