diff --git a/mp4/frma_test.go b/mp4/frma_test.go
new file mode 100644
index 0000000..fb49e7a
--- /dev/null
+++ b/mp4/frma_test.go
@@ -0,0 +1,8 @@
+package mp4
+
+import "testing"
+
+func TestFrma(t *testing.T) {
+	frma := &FrmaBox{DataFormat: "avc1"}
+	boxDiffAfterEncodeAndDecode(t, frma)
+}