diff --git a/modules/ve-mw/dm/ve.dm.MWWikitextSurfaceFragment.js b/modules/ve-mw/dm/ve.dm.MWWikitextSurfaceFragment.js
index e6f246b75a..791b8f5f66 100644
--- a/modules/ve-mw/dm/ve.dm.MWWikitextSurfaceFragment.js
+++ b/modules/ve-mw/dm/ve.dm.MWWikitextSurfaceFragment.js
@@ -173,7 +173,7 @@ ve.dm.MWWikitextSurfaceFragment.prototype.convertFromSource = function ( source
 	/*
 	ve.init.target.getSurface().createProgress(
 		parsePromise, ve.msg( 'visualeditor-generating-wikitext-progress' )
-	).done( function ( progressBar, cancelPromise ) {
+	).done( ( progressBar, cancelPromise ) => {
 		cancelPromise.fail( () => {
 			parsePromise.abort();
 		} );
diff --git a/modules/ve-mw/init/targets/ve.init.mw.ArticleTarget.js b/modules/ve-mw/init/targets/ve.init.mw.ArticleTarget.js
index 9efbef6841..3a2c1e14ff 100644
--- a/modules/ve-mw/init/targets/ve.init.mw.ArticleTarget.js
+++ b/modules/ve-mw/init/targets/ve.init.mw.ArticleTarget.js
@@ -1075,9 +1075,9 @@ ve.init.mw.ArticleTarget.prototype.getVisualDiffGeneratorPromise = function () {
 
 			return mw.libs.ve.diffLoader.getVisualDiffGeneratorPromise( target.originalDmDocPromise, newRevPromise );
 		} else {
-			return target.originalDmDocPromise.then( ( originalDmDoc ) => function () {
-				return new ve.dm.VisualDiff( originalDmDoc, target.getSurface().getModel().getAttachedRoot() );
-			} );
+			return target.originalDmDocPromise.then(
+				( originalDmDoc ) => ve.dm.VisualDiff( originalDmDoc, target.getSurface().getModel().getAttachedRoot() )
+			);
 		}
 	} );
 };
@@ -1289,7 +1289,7 @@ ve.init.mw.ArticleTarget.prototype.prepareCacheKey = function ( doc ) {
 			);
 		} )
 		.promise( {
-			abort: function () {
+			abort: () => {
 				if ( xhr ) {
 					xhr.abort();
 				}
@@ -1705,7 +1705,7 @@ ve.init.mw.ArticleTarget.prototype.submit = function ( wikitext, fields ) {
  *
  * This method performs an asynchronous action and uses a callback function to handle the result.
  *
- *     target.serialize( doc ).then( function ( data ) {
+ *     target.serialize( doc ).then( ( data ) => {
  *         // Do something with data.content (wikitext)
  *     } );
  *
diff --git a/modules/ve-mw/init/targets/ve.init.mw.DesktopArticleTarget.js b/modules/ve-mw/init/targets/ve.init.mw.DesktopArticleTarget.js
index f6bbcf1d2d..eb326991a0 100644
--- a/modules/ve-mw/init/targets/ve.init.mw.DesktopArticleTarget.js
+++ b/modules/ve-mw/init/targets/ve.init.mw.DesktopArticleTarget.js
@@ -879,10 +879,10 @@ ve.init.mw.DesktopArticleTarget.prototype.saveComplete = function ( data ) {
 	if ( !data.nocontent ) {
 		// Fix permalinks
 		if ( data.newrevid !== undefined ) {
-			$( '#t-permalink' ).add( '#coll-download-as-rl' ).find( 'a' ).each( function () {
-				var permalinkUrl = new URL( this.href );
+			$( '#t-permalink' ).add( '#coll-download-as-rl' ).find( 'a' ).each( ( i, el ) => {
+				var permalinkUrl = new URL( el.href );
 				permalinkUrl.searchParams.set( 'oldid', data.newrevid );
-				$( this ).attr( 'href', permalinkUrl.toString() );
+				$( el ).attr( 'href', permalinkUrl.toString() );
 			} );
 		}
 
diff --git a/modules/ve-mw/preinit/ve.init.mw.ArticleTargetSaver.js b/modules/ve-mw/preinit/ve.init.mw.ArticleTargetSaver.js
index 4d35e934a7..66118c9503 100644
--- a/modules/ve-mw/preinit/ve.init.mw.ArticleTargetSaver.js
+++ b/modules/ve-mw/preinit/ve.init.mw.ArticleTargetSaver.js
@@ -84,17 +84,17 @@
 					'div.donut-container', // Web of Trust (T189148)
 					'div.shield-container' // Web of Trust (T297862)
 				].join( ',' ) )
-				.each( function () {
+				.each( ( j, el ) => {
 					function truncate( text, l ) {
 						return text.length > l ? text.slice( 0, l ) + '…' : text;
 					}
-					var errorMessage = 'DOM content matching deny list found:\n' + truncate( this.outerHTML, 100 ) +
-						'\nContext:\n' + truncate( this.parentNode.outerHTML, 200 );
+					var errorMessage = 'DOM content matching deny list found:\n' + truncate( el.outerHTML, 100 ) +
+						'\nContext:\n' + truncate( el.parentNode.outerHTML, 200 );
 					mw.log.error( errorMessage );
 					var err = new Error( errorMessage );
 					err.name = 'VeDomDenyListWarning';
 					mw.errorLogger.logError( err, 'error.visualeditor' );
-					$( this ).remove();
+					$( el ).remove();
 				} );
 
 			// data-mw-section-id is copied to headings by mw.libs.ve.unwrapParsoidSections
diff --git a/modules/ve-mw/preinit/ve.init.mw.DesktopArticleTarget.init.js b/modules/ve-mw/preinit/ve.init.mw.DesktopArticleTarget.init.js
index a33dec29cd..d38bda5517 100644
--- a/modules/ve-mw/preinit/ve.init.mw.DesktopArticleTarget.init.js
+++ b/modules/ve-mw/preinit/ve.init.mw.DesktopArticleTarget.init.js
@@ -505,10 +505,10 @@
 		}
 
 		var $heading;
-		$( '#mw-content-text .mw-editsection a:not( .mw-editsection-visualeditor )' ).each( function () {
-			var linkUrl = new URL( this.href );
+		$( '#mw-content-text .mw-editsection a:not( .mw-editsection-visualeditor )' ).each( ( i, el ) => {
+			var linkUrl = new URL( el.href );
 			if ( section === parseSection( linkUrl.searchParams.get( 'section' ) ) ) {
-				$heading = $( this ).closest( '.mw-heading, h1, h2, h3, h4, h5, h6' );
+				$heading = $( el ).closest( '.mw-heading, h1, h2, h3, h4, h5, h6' );
 				return false;
 			}
 		} );
@@ -617,10 +617,10 @@
 		var visibleSectionOffset = null;
 		if ( section === null ) {
 			var firstVisibleEditSection = null;
-			$( '#firstHeading, #mw-content-text .mw-editsection' ).each( function () {
-				var top = this.getBoundingClientRect().top;
+			$( '#firstHeading, #mw-content-text .mw-editsection' ).each( ( i, el ) => {
+				var top = el.getBoundingClientRect().top;
 				if ( top > 0 ) {
-					firstVisibleEditSection = this;
+					firstVisibleEditSection = el;
 					// break
 					return false;
 				}
@@ -900,14 +900,12 @@
 		 *     mw.libs.ve.addPlugin( 'ext.gadget.foobar' );
 		 *
 		 *     // Register a callback
-		 *     mw.libs.ve.addPlugin( function ( target ) {
+		 *     mw.libs.ve.addPlugin( ( target ) => {
 		 *         ve.dm.Foobar = .....
 		 *     } );
 		 *
 		 *     // Register a callback that loads another script
-		 *     mw.libs.ve.addPlugin( function () {
-		 *         return $.getScript( 'http://example.com/foobar.js' );
-		 *     } );
+		 *     mw.libs.ve.addPlugin( () => $.getScript( 'http://example.com/foobar.js' ) );
 		 *
 		 * @param {string|Function} plugin Module name or callback that optionally returns a promise
 		 */
@@ -933,17 +931,17 @@
 					'#ca-edit a,' +
 					// Add section is currently a wikitext-only feature
 					'#ca-addsection a'
-				).each( function () {
-					if ( !this.href ) {
+				).each( ( i, el ) => {
+					if ( !el.href ) {
 						// Not a real link, probably added by a gadget or another extension (T328094)
 						return;
 					}
 
-					var linkUrl = new URL( this.href );
+					var linkUrl = new URL( el.href );
 					if ( linkUrl.searchParams.has( 'action' ) ) {
 						linkUrl.searchParams.delete( 'action' );
 						linkUrl.searchParams.set( 'veaction', 'editsource' );
-						$( this ).attr( 'href', linkUrl.toString() );
+						$( el ).attr( 'href', linkUrl.toString() );
 					}
 				} );
 			}
diff --git a/modules/ve-mw/preinit/ve.init.mw.DiffLoader.js b/modules/ve-mw/preinit/ve.init.mw.DiffLoader.js
index b7083ee471..7a46c68f4f 100644
--- a/modules/ve-mw/preinit/ve.init.mw.DiffLoader.js
+++ b/modules/ve-mw/preinit/ve.init.mw.DiffLoader.js
@@ -62,12 +62,15 @@
 					false,
 					// noMetadata, we only use `content` in getModelFromResponse
 					true
-				).then( ( response ) => parseDocumentModulePromise.then( () => mw.libs.ve.diffLoader.getModelFromResponse( response, section ) ), function () {
+				).then(
+					( response ) => parseDocumentModulePromise.then( () => mw.libs.ve.diffLoader.getModelFromResponse( response, section ) ),
+					() => {
 					// Clear promise. Do not cache errors.
-					delete revCache[ cacheKey ];
-					// Let caller handle the error code
-					return $.Deferred().rejectWith( this, arguments );
-				} );
+						delete revCache[ cacheKey ];
+						// Let caller handle the error code
+						return $.Deferred().rejectWith( this, arguments );
+					}
+				);
 
 			return revCache[ cacheKey ];
 		},
@@ -93,9 +96,7 @@
 				// TODO: Differ expects newDoc to be derived from oldDoc and contain all its store data.
 				// We may want to remove that assumption from the differ?
 				newDoc.getStore().merge( oldDoc.getStore() );
-				return function () {
-					return new ve.dm.VisualDiff( oldDoc, newDoc );
-				};
+				return () => new ve.dm.VisualDiff( oldDoc, newDoc );
 			} );
 		}
 
diff --git a/modules/ve-mw/tests/dm/annotations/ve.dm.MWInternalLinkAnnotation.test.js b/modules/ve-mw/tests/dm/annotations/ve.dm.MWInternalLinkAnnotation.test.js
index f4f9f2bfef..b4fc7a61b9 100644
--- a/modules/ve-mw/tests/dm/annotations/ve.dm.MWInternalLinkAnnotation.test.js
+++ b/modules/ve-mw/tests/dm/annotations/ve.dm.MWInternalLinkAnnotation.test.js
@@ -181,7 +181,7 @@ QUnit.test( 'toDataElement', ( assert ) => {
 		}
 	];
 
-	articlePaths.forEach( function ( pathData ) {
+	articlePaths.forEach( ( pathData ) => {
 		// Set up global state (site configuration)
 		mw.config.set( pathData.config );
 
@@ -196,14 +196,13 @@ QUnit.test( 'toDataElement', ( assert ) => {
 		converter.fromClipboard = true;
 
 		// Generate test cases for this site configuration
-		const cases = getCases();
-		for ( let i = 0; i < cases.length; i++ ) {
+		getCases().forEach( ( caseItem ) => {
 			assert.deepEqual(
-				ve.dm.MWInternalLinkAnnotation.static.toDataElement( [ cases[ i ].element ], converter ),
-				cases[ i ].expected,
-				cases[ i ].msg + ': ' + pathData.msg
+				ve.dm.MWInternalLinkAnnotation.static.toDataElement( [ caseItem.element ], converter ),
+				caseItem.expected,
+				caseItem.msg + ': ' + pathData.msg
 			);
-		}
+		} );
 	} );
 } );
 
diff --git a/modules/ve-mw/tests/dm/models/ve.dm.MWTemplateSpecModel.test.js b/modules/ve-mw/tests/dm/models/ve.dm.MWTemplateSpecModel.test.js
index e403dc0ca2..aede08f4fb 100644
--- a/modules/ve-mw/tests/dm/models/ve.dm.MWTemplateSpecModel.test.js
+++ b/modules/ve-mw/tests/dm/models/ve.dm.MWTemplateSpecModel.test.js
@@ -12,8 +12,10 @@
 		} );
 		return {
 			params,
-			getTemplateDataQueryTitle: () => null,
-			getTarget: () => {
+			getTemplateDataQueryTitle: function () {
+				return null;
+			},
+			getTarget: function () {
 				return { wt: 'RawTemplateName' };
 			},
 			getParameters: function () {
diff --git a/modules/ve-mw/ui/widgets/ve.ui.MWExternalLinkAnnotationWidget.js b/modules/ve-mw/ui/widgets/ve.ui.MWExternalLinkAnnotationWidget.js
index ab76948e87..e423f52815 100644
--- a/modules/ve-mw/ui/widgets/ve.ui.MWExternalLinkAnnotationWidget.js
+++ b/modules/ve-mw/ui/widgets/ve.ui.MWExternalLinkAnnotationWidget.js
@@ -54,9 +54,7 @@ ve.ui.MWExternalLinkAnnotationWidget.static.createExternalLinkInputWidget = func
 	var inputWidget = new OO.ui.TextInputWidget( ve.extendObject( {}, config, {
 		icon: 'linkExternal',
 		type: 'url',
-		validate: function ( text ) {
-			return !!ve.init.platform.getExternalLinkUrlProtocolsRegExp().exec( text.trim() );
-		}
+		validate: ( text ) => !!ve.init.platform.getExternalLinkUrlProtocolsRegExp().exec( text.trim() )
 	} ) );
 
 	inputWidget.$input.attr( 'aria-label', mw.msg( 'visualeditor-linkinspector-button-link-external' ) );