diff --git a/dom/media/webm/IntelWebMVideoDecoder.cpp b/dom/media/webm/IntelWebMVideoDecoder.cpp
index 7f17f120da9..448c238ef48 100644
--- a/dom/media/webm/IntelWebMVideoDecoder.cpp
+++ b/dom/media/webm/IntelWebMVideoDecoder.cpp
@@ -200,7 +200,7 @@ IntelWebMVideoDecoder::Demux(nsRefPtr<VP8Sample>& aSample, bool* aEOS)
   }
 
   vpx_codec_stream_info_t si;
-  memset(&si, 0, sizeof(si));
+  PodZero(&si);
   si.sz = sizeof(si);
   if (mReader->GetVideoCodec() == NESTEGG_CODEC_VP8) {
     vpx_codec_peek_stream_info(vpx_codec_vp8_dx(), data, length, &si);
diff --git a/dom/media/webm/SoftwareWebMVideoDecoder.cpp b/dom/media/webm/SoftwareWebMVideoDecoder.cpp
index fa395a51354..ce89cd948aa 100644
--- a/dom/media/webm/SoftwareWebMVideoDecoder.cpp
+++ b/dom/media/webm/SoftwareWebMVideoDecoder.cpp
@@ -30,7 +30,7 @@ SoftwareWebMVideoDecoder::SoftwareWebMVideoDecoder(WebMReader* aReader)
     mReader(aReader)
 {
   MOZ_COUNT_CTOR(SoftwareWebMVideoDecoder);
-  memset(&mVPX, 0, sizeof(vpx_codec_ctx_t));
+  PodZero(&mVPX);
 }
 
 SoftwareWebMVideoDecoder::~SoftwareWebMVideoDecoder()
@@ -128,7 +128,7 @@ SoftwareWebMVideoDecoder::DecodeVideoFrame(bool &aKeyframeSkip,
   }
 
   vpx_codec_stream_info_t si;
-  memset(&si, 0, sizeof(si));
+  PodZero(&si);
   si.sz = sizeof(si);
   if (mReader->GetVideoCodec() == NESTEGG_CODEC_VP8) {
     vpx_codec_peek_stream_info(vpx_codec_vp8_dx(), data, length, &si);