diff --git a/media/libaudiohal/EffectHalHidl.cpp b/media/libaudiohal/EffectHalHidl.cpp
index 3fb2f43..2665719 100644
--- a/media/libaudiohal/EffectHalHidl.cpp
+++ b/media/libaudiohal/EffectHalHidl.cpp
@@ -171,6 +171,8 @@
         hidlData.setToExternal(reinterpret_cast<uint8_t*>(pCmdData), cmdSize);
     }
     status_t status;
+    uint32_t replySizeStub = 0;
+    if (replySize == nullptr) replySize = &replySizeStub;
     Return<void> ret = mEffect->command(cmdCode, hidlData, *replySize,
             [&](int32_t s, const hidl_vec<uint8_t>& result) {
                 status = s;