diff --git a/src/validate/html/index.js b/src/validate/html/index.js
index 7c791a600b..13b627f73a 100644
--- a/src/validate/html/index.js
+++ b/src/validate/html/index.js
@@ -4,9 +4,9 @@ import validateWindow from './validateWindow.js';
 
 const svg = /^(?:altGlyph|altGlyphDef|altGlyphItem|animate|animateColor|animateMotion|animateTransform|circle|clipPath|color-profile|cursor|defs|desc|discard|ellipse|feBlend|feColorMatrix|feComponentTransfer|feComposite|feConvolveMatrix|feDiffuseLighting|feDisplacementMap|feDistantLight|feDropShadow|feFlood|feFuncA|feFuncB|feFuncG|feFuncR|feGaussianBlur|feImage|feMerge|feMergeNode|feMorphology|feOffset|fePointLight|feSpecularLighting|feSpotLight|feTile|feTurbulence|filter|font|font-face|font-face-format|font-face-name|font-face-src|font-face-uri|foreignObject|g|glyph|glyphRef|hatch|hatchpath|hkern|image|line|linearGradient|marker|mask|mesh|meshgradient|meshpatch|meshrow|metadata|missing-glyph|mpath|path|pattern|polygon|polyline|radialGradient|rect|set|solidcolor|stop|switch|symbol|text|textPath|title|tref|tspan|unknown|use|view|vkern)$/;
 
-const meta = {
-	':Window': validateWindow
-};
+const meta = new Map([
+	[ ':Window', validateWindow ]
+]);
 
 export default function validateHtml ( validator, html ) {
 	let elementDepth = 0;
@@ -17,8 +17,8 @@ export default function validateHtml ( validator, html ) {
 				validator.warn( `<${node.name}> is an SVG element – did you forget to add { namespace: 'svg' } ?`, node.start );
 			}
 
-			if ( node.name in meta ) {
-				return meta[ node.name ]( validator, node );
+			if ( meta.has( node.name ) ) {
+				return meta.get( node.name )( validator, node );
 			}
 
 			elementDepth += 1;