diff --git a/src/matchers/is-number.spec.ts b/src/matchers/is-number.spec.ts
index 8bb14bb..9454985 100644
--- a/src/matchers/is-number.spec.ts
+++ b/src/matchers/is-number.spec.ts
@@ -48,4 +48,16 @@ describe('isNumber', () => {
   it('should pretty print', () => {
     expect(isNumber().toJSON()).toEqual('number');
   });
+
+  it('should return diff', () => {
+    expect(isNumber().getDiff('NaN')).toEqual({
+      expected: 'number',
+      actual: '"NaN" (string)',
+    });
+
+    expect(isNumber().getDiff({ foo: 'bar' })).toEqual({
+      expected: 'number',
+      actual: '{"foo": "bar"} (object)',
+    });
+  });
 });
diff --git a/src/matchers/is-number.ts b/src/matchers/is-number.ts
index 600bfa7..4aec262 100644
--- a/src/matchers/is-number.ts
+++ b/src/matchers/is-number.ts
@@ -1,3 +1,5 @@
+import stripAnsi from 'strip-ansi';
+import { printArg } from '../print';
 import type { TypeMatcher } from './matcher';
 import { matches } from './matcher';
 
@@ -14,4 +16,8 @@ import { matches } from './matcher';
 export const isNumber = (): TypeMatcher<number> =>
   matches((actual) => typeof actual === 'number' && !Number.isNaN(actual), {
     toJSON: () => 'number',
+    getDiff: (actual) => ({
+      actual: `${stripAnsi(printArg(actual, true))} (${typeof actual})`,
+      expected: 'number',
+    }),
   });