diff --git a/lib/config-util.js b/lib/config-util.js
index 8515b85ef..d8b8cf618 100644
--- a/lib/config-util.js
+++ b/lib/config-util.js
@@ -116,7 +116,7 @@ Config.buildYargs = function (cwd) {
       global: false
     })
     .option('es-modules', {
-      default: false,
+      default: true,
       type: 'boolean',
       describe: 'tell the instrumenter to treat files as ES Modules',
       global: false
diff --git a/test/nyc-bin.js b/test/nyc-bin.js
index e72170083..6103da369 100644
--- a/test/nyc-bin.js
+++ b/test/nyc-bin.js
@@ -1035,6 +1035,7 @@ describe('the nyc cli', function () {
       const args = [
         bin,
         '--cache', 'false',
+        '--es-modules', 'false',
         process.execPath, './not-strict.js'
       ]
 
@@ -1065,7 +1066,6 @@ describe('the nyc cli', function () {
       const args = [
         bin,
         '--cache', 'false',
-        '--es-modules', 'true',
         '--exit-on-error', 'true',
         process.execPath, './not-strict.js'
       ]