diff --git a/example-esm/lib/foo.json b/example-esm/lib/foo.json
new file mode 100644
index 0000000..99de2d7
--- /dev/null
+++ b/example-esm/lib/foo.json
@@ -0,0 +1,3 @@
+{
+  "quibble": "rocks"
+}
diff --git a/example-esm/test/helper.js b/example-esm/test/helper.js
index fc0fc3f..f24aa8f 100644
--- a/example-esm/test/helper.js
+++ b/example-esm/test/helper.js
@@ -4,6 +4,7 @@ const quibble = require('quibble')
 beforeEach(function () {
   quibble.esm('../lib/animals/bear.mjs', undefined, function () { return 'a fake bear' })
   quibble.esm('../lib/animals/lion.mjs', undefined, function () { return 'a fake lion' })
+  quibble.esm('../lib/foo.json', undefined, { 'hello': 'quibble' })
 })
 
 afterEach(function () {
diff --git a/example-esm/test/lib/zoo-spec.mjs b/example-esm/test/lib/zoo-spec.mjs
index 0a7aba7..aa75a2b 100644
--- a/example-esm/test/lib/zoo-spec.mjs
+++ b/example-esm/test/lib/zoo-spec.mjs
@@ -5,9 +5,11 @@ const { expect } = chai
 
 describe('zoo', function () {
   var subject
+  var json
 
   beforeEach(async function () {
     subject = await import('../../lib/zoo.mjs')
+    json = await import('../../lib/foo.json')
   })
 
   it('contains a fake bear', function () {
@@ -17,4 +19,8 @@ describe('zoo', function () {
   it('contains a fake lion', function () {
     expect(subject.default().animals).to.contain('a fake lion')
   })
+
+  it('manipulates json', function () {
+    expect(json.default).to.deep.equal({ hello: 'quibble' })
+  })
 })
diff --git a/lib/quibble.mjs b/lib/quibble.mjs
index a97707a..924be13 100644
--- a/lib/quibble.mjs
+++ b/lib/quibble.mjs
@@ -114,8 +114,9 @@ ${
  */
 export async function load (url, context, defaultLoad) {
   const stubsInfo = getStubsInfo(new URL(url))
+  const isJson = url.endsWith('.json')
 
   return stubsInfo
-    ? { source: transformModuleSource(stubsInfo), format: 'module' }
+    ? { source: transformModuleSource(stubsInfo), format: isJson ? 'json' : 'module' }
     : defaultLoad(url, context, defaultLoad)
 }