diff --git a/includes/TemplateDataBlob.php b/includes/TemplateDataBlob.php
index 8a485f34..c7b6d96b 100644
--- a/includes/TemplateDataBlob.php
+++ b/includes/TemplateDataBlob.php
@@ -165,7 +165,7 @@ class TemplateDataBlob {
 			if ( !is_object( $data->description ) && !is_string( $data->description ) ) {
 				return Status::newFatal( 'templatedata-invalid-type', 'description', 'string|object' );
 			}
-			$data->description = self::normaliseInterfaceText( $data->description );
+			$data->description = $this->normaliseInterfaceText( $data->description );
 		} else {
 			$data->description = null;
 		}
@@ -230,7 +230,7 @@ class TemplateDataBlob {
 						'string|object'
 					);
 				}
-				$paramObj->label = self::normaliseInterfaceText( $paramObj->label );
+				$paramObj->label = $this->normaliseInterfaceText( $paramObj->label );
 			} else {
 				$paramObj->label = null;
 			}
@@ -271,7 +271,7 @@ class TemplateDataBlob {
 						'string|object'
 					);
 				}
-				$paramObj->description = self::normaliseInterfaceText( $paramObj->description );
+				$paramObj->description = $this->normaliseInterfaceText( $paramObj->description );
 			} else {
 				$paramObj->description = null;
 			}
@@ -286,7 +286,7 @@ class TemplateDataBlob {
 						'string|object'
 					);
 				}
-				$paramObj->example = self::normaliseInterfaceText( $paramObj->example );
+				$paramObj->example = $this->normaliseInterfaceText( $paramObj->example );
 			} else {
 				$paramObj->example = null;
 			}
@@ -342,7 +342,7 @@ class TemplateDataBlob {
 						'string|object'
 					);
 				}
-				$paramObj->default = self::normaliseInterfaceText( $paramObj->default );
+				$paramObj->default = $this->normaliseInterfaceText( $paramObj->default );
 			} else {
 				$paramObj->default = null;
 			}
@@ -461,7 +461,7 @@ class TemplateDataBlob {
 				);
 			}
 
-			$setObj->label = self::normaliseInterfaceText( $setObj->label );
+			$setObj->label = $this->normaliseInterfaceText( $setObj->label );
 
 			if ( !isset( $setObj->params ) ) {
 				return Status::newFatal( 'templatedata-invalid-missing', "sets.{$setNr}.params", 'array' );
@@ -558,9 +558,9 @@ class TemplateDataBlob {
 	/**
 	 * Normalise a InterfaceText field in the TemplateData blob.
 	 * @param stdClass|string $text
-	 * @return stdClass|string
+	 * @return stdClass
 	 */
-	protected static function normaliseInterfaceText( $text ) {
+	private function normaliseInterfaceText( $text ) {
 		if ( is_string( $text ) ) {
 			$contLang = MediaWikiServices::getInstance()->getContentLanguage();
 			return (object)[ $contLang->getCode() => $text ];