diff --git a/README.md b/README.md
index 8ab1abe..c23bef4 100644
--- a/README.md
+++ b/README.md
@@ -32,7 +32,7 @@ module.exports = {
 ## Usage
 Use the only 3 apis for test cases:
 
-* `mockFlags(flags: LDFlagSet)`: mock flags at the start of each test case.
+`mockFlags(flags: LDFlagSet)`: mock flags at the start of each test case.
 
 * `ldClientMock`: a jest mock of the [ldClient](https://launchdarkly.github.io/js-client-sdk/interfaces/_launchdarkly_js_client_sdk_.ldclient.html). All
 methods of this object are jest mocks.
diff --git a/src/index.test.ts b/src/index.test.ts
index 38260ac..a6dccd1 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -25,6 +25,17 @@ describe('main', () => {
     expect(current['dev-test-flag']).toBeTruthy()
   })
 
+  test('mock option without case formatting correctly', () => {
+    mockFlags({ DEV_test_Flag: true })
+
+    const {
+      result: { current },
+    } = renderHook(() => useFlags())
+
+    expect(current.DEV_test_Flag).toBeTruthy()
+    expect(current['DEV_test_Flag']).toBeTruthy()
+  })
+
   test('mock asyncWithLDProvider correctly', () => {
     expect(asyncWithLDProvider).toBeDefined()
   })
diff --git a/src/index.ts b/src/index.ts
index d85119e..c8917f3 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -61,6 +61,7 @@ export const mockFlags = (flags: LDFlagSet) => {
       const camel = camelCase(k)
       result[kebab] = flags[k]
       result[camel] = flags[k]
+      result[k] = flags[k]
     })
     return result
   })