diff --git a/test/DumpDecoderClient.cxx b/test/DumpDecoderClient.cxx
index f107cc53a..23664b0a4 100644
--- a/test/DumpDecoderClient.cxx
+++ b/test/DumpDecoderClient.cxx
@@ -121,7 +121,7 @@ DumpReplayGainTuple(const char *name, const ReplayGainTuple &tuple) noexcept
 {
 	if (tuple.IsDefined())
 		fprintf(stderr, "replay_gain[%s]: gain=%f peak=%f\n",
-			name, tuple.gain, tuple.peak);
+			name, (double)tuple.gain, (double)tuple.peak);
 }
 
 static void