diff --git a/test/testdata/fix/in/mirror.go b/test/testdata/fix/in/mirror.go
new file mode 100644
index 000000000000..94c0637f3dee
--- /dev/null
+++ b/test/testdata/fix/in/mirror.go
@@ -0,0 +1,11 @@
+//golangcitest:args -Emirror
+//golangcitest:expected_exitcode 0
+package testdata
+
+import (
+	"unicode/utf8"
+)
+
+func foobar() {
+	_ = utf8.RuneCount([]byte("foobar"))
+}
diff --git a/test/testdata/fix/out/mirror.go b/test/testdata/fix/out/mirror.go
new file mode 100644
index 000000000000..05cbc5447752
--- /dev/null
+++ b/test/testdata/fix/out/mirror.go
@@ -0,0 +1,11 @@
+//golangcitest:args -Emirror
+//golangcitest:expected_exitcode 0
+package testdata
+
+import (
+	"unicode/utf8"
+)
+
+func foobar() {
+	_ = utf8.RuneCountInString("foobar")
+}