diff --git a/packages/core/src/utils/mergeAttributes.ts b/packages/core/src/utils/mergeAttributes.ts
index 136e3c5b..733c8cb9 100644
--- a/packages/core/src/utils/mergeAttributes.ts
+++ b/packages/core/src/utils/mergeAttributes.ts
@@ -5,18 +5,19 @@ export default function mergeAttributes(...object: AnyObject[]) {
     const mergedAttributes = { ...items }
 
     Object.entries(item).forEach(([key, value]) => {
-      if (!mergedAttributes[key]) {
+      const exists = mergedAttributes[key]
+
+      if (!exists) {
         mergedAttributes[key] = value
         return
       }
 
       if (key === 'class') {
         mergedAttributes[key] = [mergedAttributes[key], value].join(' ')
-        return
-      }
-
-      if (key === 'style') {
+      } else if (key === 'style') {
         mergedAttributes[key] = [mergedAttributes[key], value].join('; ')
+      } else {
+        mergedAttributes[key] = value
       }
     })
 
diff --git a/tests/cypress/integration/core/mergeAttributes.spec.ts b/tests/cypress/integration/core/mergeAttributes.spec.ts
new file mode 100644
index 00000000..5a6a24e0
--- /dev/null
+++ b/tests/cypress/integration/core/mergeAttributes.spec.ts
@@ -0,0 +1,60 @@
+/// <reference types="cypress" />
+
+import mergeAttributes from '@tiptap/core/src/utils/mergeAttributes'
+
+describe('mergeAttributes', () => {
+  it('should merge two objects', () => {
+    const value = mergeAttributes({ id: 1 }, { class: 'foo' })
+
+    expect(value).to.deep.eq({
+      id: 1,
+      class: 'foo',
+    })
+  })
+
+  it('should merge multiple objects', () => {
+    const value = mergeAttributes({ id: 1 }, { class: 'foo' }, { title: 'bar' })
+
+    expect(value).to.deep.eq({
+      id: 1,
+      class: 'foo',
+      title: 'bar',
+    })
+  })
+
+  it('should overwrite values', () => {
+    const value = mergeAttributes({ id: 1 }, { id: 2 })
+
+    expect(value).to.deep.eq({
+      id: 2,
+    })
+  })
+
+  it('should merge classes', () => {
+    const value = mergeAttributes({ class: 'foo' }, { class: 'bar' })
+
+    expect(value).to.deep.eq({
+      class: 'foo bar',
+    })
+  })
+
+  it('should merge styles', () => {
+    const value = mergeAttributes({ style: 'color: red' }, { style: 'background: green' })
+
+    expect(value).to.deep.eq({
+      style: 'color: red; background: green',
+    })
+  })
+
+  it('should merge classes and styles', () => {
+    const value = mergeAttributes(
+      { class: 'foo', style: 'color: red' },
+      { class: 'bar', style: 'background: green' },
+    )
+
+    expect(value).to.deep.eq({
+      class: 'foo bar',
+      style: 'color: red; background: green',
+    })
+  })
+})