diff --git a/aos/flatbuffer_merge_test.cc b/aos/flatbuffer_merge_test.cc
index 079eb11..371639a 100644
--- a/aos/flatbuffer_merge_test.cc
+++ b/aos/flatbuffer_merge_test.cc
@@ -20,6 +20,13 @@
     const ::std::string merged_output =
         FlatbufferToJson(fb_merged, ConfigurationTypeTable());
     EXPECT_EQ(expected_output, merged_output);
+
+    aos::FlatbufferDetachedBuffer<Configuration> expected_message(
+        JsonToFlatbuffer(std::string(expected_output).c_str(),
+                         ConfigurationTypeTable()));
+    EXPECT_TRUE(
+        CompareFlatBuffer(flatbuffers::GetRoot<Configuration>(fb_merged.data()),
+                          &expected_message.message()));
   }
 
   void JsonMerge(const ::std::string in1, const ::std::string in2,
@@ -335,6 +342,18 @@
             "\"name\": \"woo2\" }, { \"name\": \"wo3\" } ] }");
 }
 
+// Tests a compare of 2 basic (different) messages.
+TEST_F(FlatbufferMerge, CompareDifferent) {
+  aos::FlatbufferDetachedBuffer<Configuration> message1(JsonToFlatbuffer(
+      "{ \"single_application\": { \"name\": \"wow\", \"priority\": 7 } }",
+      ConfigurationTypeTable()));
+  aos::FlatbufferDetachedBuffer<Configuration> message2(JsonToFlatbuffer(
+      "{ \"single_application\": { \"name\": \"wow\", \"priority\": 8 } }",
+      ConfigurationTypeTable()));
+
+  EXPECT_FALSE(CompareFlatBuffer(&message1.message(), &message2.message()));
+}
+
 // TODO(austin): enums
 // TODO(austin): unions
 // TODO(austin): struct