diff --git a/audio/aidl/vts/EffectHelper.h b/audio/aidl/vts/EffectHelper.h
index c58ed13..e4edd10 100644
--- a/audio/aidl/vts/EffectHelper.h
+++ b/audio/aidl/vts/EffectHelper.h
@@ -217,6 +217,7 @@
         input.frameCount = iFrameCount;
         output.base.sampleRate = oSampleRate;
         output.base.channelMask = mOutputChannelLayout;
+        output.base.format = DefaultFormat;
         output.frameCount = oFrameCount;
         inputFrameSize = android::hardware::audio::common::getFrameSizeInBytes(
                 input.base.format, input.base.channelMask);