diff --git a/packages/happy-dom/src/query-selector/SelectorItem.ts b/packages/happy-dom/src/query-selector/SelectorItem.ts
index a5aa0ead4..dc0b2389b 100644
--- a/packages/happy-dom/src/query-selector/SelectorItem.ts
+++ b/packages/happy-dom/src/query-selector/SelectorItem.ts
@@ -7,6 +7,7 @@ const ATTRIBUTE_NAME_REGEXP = /[^a-zA-Z0-9-_$]/;
 const PSUEDO_REGEXP = /:([a-zA-Z-]+)\(([0-9n+-]+|odd|even)\)|:not\(([^)]+)\)|:([a-zA-Z-]+)/g;
 const CLASS_REGEXP = /\.([a-zA-Z0-9-_$]+)/g;
 const TAG_NAME_REGEXP = /^[a-zA-Z0-9-]+/;
+const ID_REGEXP = /#[A-Za-z][-A-Za-z0-9_]*/g;
 
 /**
  * Selector item.
@@ -31,16 +32,22 @@ export default class SelectorItem {
 		const baseSelector = selector.replace(new RegExp(PSUEDO_REGEXP, 'g'), '');
 
 		this.isAll = baseSelector === '*';
-		this.isID = !this.isAll ? selector.startsWith('#') : false;
-		this.isAttribute = !this.isAll && !this.isID && baseSelector.includes('[');
+		this.isID = !this.isAll ? selector.indexOf('#') !== -1 : false;
+		this.isAttribute = !this.isAll && baseSelector.includes('[');
 		// If baseSelector !== selector then some psuedo selector was replaced above
-		this.isPseudo = !this.isAll && !this.isID && baseSelector !== selector;
-		this.isClass = !this.isAll && !this.isID && new RegExp(CLASS_REGEXP, 'g').test(baseSelector);
-		this.tagName = !this.isAll && !this.isID ? baseSelector.match(TAG_NAME_REGEXP) : null;
+		this.isPseudo = !this.isAll && baseSelector !== selector;
+		this.isClass = !this.isAll && new RegExp(CLASS_REGEXP, 'g').test(baseSelector);
+		this.tagName = !this.isAll ? baseSelector.match(TAG_NAME_REGEXP) : null;
 		this.tagName = this.tagName ? this.tagName[0].toUpperCase() : null;
 		this.isTagName = this.tagName !== null;
 		this.selector = selector;
-		this.id = !this.isAll && this.isID ? baseSelector.replace('#', '') : null;
+		this.id = null;
+		if (!this.isAll && this.isID) {
+			const idMatches = baseSelector.match(ID_REGEXP);
+			if (idMatches) {
+				this.id = idMatches[0].replace('#', '');
+			}
+		}
 	}
 
 	/**
@@ -59,7 +66,9 @@ export default class SelectorItem {
 
 		// ID Match
 		if (this.isID) {
-			return this.id === element.id;
+			if (this.id !== element.id) {
+				return false;
+			}
 		}
 
 		// Tag name match
diff --git a/packages/happy-dom/test/query-selector/QuerySelector.test.ts b/packages/happy-dom/test/query-selector/QuerySelector.test.ts
index f95192bff..305ea6925 100644
--- a/packages/happy-dom/test/query-selector/QuerySelector.test.ts
+++ b/packages/happy-dom/test/query-selector/QuerySelector.test.ts
@@ -560,6 +560,16 @@ describe('QuerySelector', () => {
 			expect(div1.querySelector('span.spanClass')).toBe(span);
 		});
 
+		it('Returns div with a specific id and tag name matching "div#divId".', () => {
+			const div1 = document.createElement('div');
+			const div2 = document.createElement('div');
+			const div3 = document.createElement('div');
+			div3.id = 'divId';
+			div1.appendChild(div2);
+			div2.appendChild(div3);
+			expect(div1.querySelector('div#divId')).toBe(div3);
+		});
+
 		it('Returns span with a specific class name and tag name matching "custom-element.class1".', () => {
 			const div = document.createElement('div');
 			const customElement1 = document.createElement('custom-element');