diff --git a/tests/test_synchdata.cpp b/tests/test_synchdata.cpp
index 59b43b67..04ef5359 100644
--- a/tests/test_synchdata.cpp
+++ b/tests/test_synchdata.cpp
@@ -70,7 +70,7 @@ public:
   void testDecode1()
   {
     ByteVector a("\xff\x00\x00", 3);
-    ID3v2::SynchData::decode(a);
+    a = ID3v2::SynchData::decode(a);
     CPPUNIT_ASSERT_EQUAL((unsigned int)2, a.size());
     CPPUNIT_ASSERT_EQUAL(ByteVector("\xff\x00", 2), a);
   }
@@ -78,7 +78,7 @@ public:
   void testDecode2()
   {
     ByteVector a("\xff\x44", 2);
-    ID3v2::SynchData::decode(a);
+    a = ID3v2::SynchData::decode(a);
     CPPUNIT_ASSERT_EQUAL((unsigned int)2, a.size());
     CPPUNIT_ASSERT_EQUAL(ByteVector("\xff\x44", 2), a);
   }