diff --git a/AbuseFilter.class.php b/AbuseFilter.class.php
index 7497a6805..8999d82e1 100644
--- a/AbuseFilter.class.php
+++ b/AbuseFilter.class.php
@@ -2063,4 +2063,37 @@ class AbuseFilter {
 		$msg = "abusefilter-group-$group";
 		return wfMessage($msg)->exists() ? wfMessage($msg)->escaped() : $group;
 	}
+
+	/**
+	 * Look up some text of a revision from its revision id
+	 *
+	 * Note that this is really *some* text, we do not make *any* guarantee
+	 * that this text will be even close to what the user actually sees, or
+	 * that the form is fit for any intended purpose.
+	 *
+	 * Note also that if the revision for any reason is not an Revision
+	 * the function returns with an empty string.
+	 *
+	 * @param Revision $revision a valid revision
+	 * @param $audience Integer: one of:
+	 *      Revision::FOR_PUBLIC       to be displayed to all users
+	 *      Revision::FOR_THIS_USER    to be displayed to the given user
+	 *      Revision::RAW              get the text regardless of permissions
+	 * @return string|null the content of the revision as some kind of string,
+	 * 		or an empty string if it can not be found
+	 */
+	static function revisionToString( $revision, $audience = Revision::FOR_PUBLIC ) {
+		if ( !$revision instanceof Revision ) {
+			return '';
+		}
+		if ( defined( 'MW_SUPPORTS_CONTENTHANDLER' ) ) {
+			$content = $revision->getContent( $audience );
+			$result = $content instanceof TextContent ? $content->getNativeData() : $content->getTextForSearchIndex();
+		} else {
+			// For MediaWiki without contenthandler support (< 1.21)
+			$result = $revision->getText();
+		}
+		return $result;
+	}
+
 }
diff --git a/AbuseFilter.hooks.php b/AbuseFilter.hooks.php
index da3034b9c..cd531a286 100644
--- a/AbuseFilter.hooks.php
+++ b/AbuseFilter.hooks.php
@@ -37,7 +37,7 @@ class AbuseFilterHooks {
 			if ( !$revision ) {
 				return true;
 			}
-			$oldtext = $revision->getRawText();
+			$oldtext = AbuseFilter::revisionToString( $revision, Revision::RAW );
 		}
 
 		// Cache article object so we can share a parse operation
diff --git a/AbuseFilterVariableHolder.php b/AbuseFilterVariableHolder.php
index 3d5799710..72473dc0f 100644
--- a/AbuseFilterVariableHolder.php
+++ b/AbuseFilterVariableHolder.php
@@ -326,7 +326,7 @@ class AFComputedVariable {
 				break;
 			case 'parse-wikitext':
 				// Should ONLY be used when sharing a parse operation with the edit.
-	
+
 				$article = $parameters['article'];
 				if ( $article ) {
 					$textVar = $parameters['wikitext-var'];
@@ -436,20 +436,14 @@ class AFComputedVariable {
 				break;
 			case 'revision-text-by-id':
 				$rev = Revision::newFromId( $parameters['revid'] );
-				$result = $rev->getText();
+				$result = AbuseFilter::revisionToString( $rev );
 				break;
 			case 'revision-text-by-timestamp':
 				$timestamp = $parameters['timestamp'];
 				$title = Title::makeTitle( $parameters['namespace'], $parameters['title'] );
 				$dbr = wfGetDB( DB_SLAVE );
-
 				$rev = Revision::loadFromTimestamp( $dbr, $title, $timestamp );
-
-				if ( $rev ) {
-					$result = $rev->getText();
-				} else {
-					$result = '';
-				}
+				$result = AbuseFilter::revisionToString( $rev );
 				break;
 			default:
 				if ( wfRunHooks( 'AbuseFilter-computeVariable',