diff --git a/media/omx-plugin/OmxPlugin.cpp b/media/omx-plugin/OmxPlugin.cpp
index 81cf3d3d946..d87ab79dde5 100644
--- a/media/omx-plugin/OmxPlugin.cpp
+++ b/media/omx-plugin/OmxPlugin.cpp
@@ -277,7 +277,7 @@ enum ColorFormatSupport {
 static ColorFormatSupport
 IsColorFormatSupported(OMX_COLOR_FORMATTYPE aColorFormat)
 {
-  switch (aColorFormat) {
+  switch (static_cast<int>(aColorFormat)) {
     case OMX_COLOR_FormatCbYCrY:
     case OMX_COLOR_FormatYUV420Planar:
     case OMX_COLOR_FormatYUV420SemiPlanar:
@@ -346,7 +346,7 @@ FindPreferredDecoderAndColorFormat(const sp<IOMX>& aOmx,
 
       if (supported) {
         strncpy(aDecoderName, caps.mComponentName.string(), aDecoderLen);
-        *aColorFormat = (OMX_COLOR_FORMATTYPE)color;
+        *aColorFormat = color;
         found = true;
       }
 
@@ -727,7 +727,7 @@ void OmxDecoder::ToVideoFrame_YUV420SemiPlanar(VideoFrame *aFrame, int64_t aTime
   // to see if the video size patches the raw width and height. If so we can
   // use those figures instead.
 
-  if (aSize == mVideoWidth * mVideoHeight * 3 / 2) {
+  if (static_cast<int>(aSize) == mVideoWidth * mVideoHeight * 3 / 2) {
     videoStride = mVideoWidth;
     videoSliceHeight = mVideoHeight;
   }
diff --git a/media/omx-plugin/froyo/moz.build b/media/omx-plugin/froyo/moz.build
index f04155c4a03..9a6408e86f0 100644
--- a/media/omx-plugin/froyo/moz.build
+++ b/media/omx-plugin/froyo/moz.build
@@ -20,3 +20,6 @@ LOCAL_INCLUDES += [
 
 # Don't use STL wrappers; this isn't Gecko code
 DISABLE_STL_WRAPPING = True
+
+# Suppress warnings in third-party code.
+CXXFLAGS += ['-Wno-multichar']
diff --git a/media/omx-plugin/gb/moz.build b/media/omx-plugin/gb/moz.build
index 3829c3b9c05..6b134e31fb0 100644
--- a/media/omx-plugin/gb/moz.build
+++ b/media/omx-plugin/gb/moz.build
@@ -20,3 +20,6 @@ LOCAL_INCLUDES += [
 
 # Don't use STL wrappers; this isn't Gecko code
 DISABLE_STL_WRAPPING = True
+
+# Suppress warnings in third-party code.
+CXXFLAGS += ['-Wno-multichar']
diff --git a/media/omx-plugin/gb235/moz.build b/media/omx-plugin/gb235/moz.build
index fc2b8b76a46..3da31a7860a 100644
--- a/media/omx-plugin/gb235/moz.build
+++ b/media/omx-plugin/gb235/moz.build
@@ -20,3 +20,6 @@ LOCAL_INCLUDES += [
 
 # Don't use STL wrappers; this isn't Gecko code
 DISABLE_STL_WRAPPING = True
+
+# Suppress warnings in third-party code.
+CXXFLAGS += ['-Wno-multichar']
diff --git a/media/omx-plugin/hc/moz.build b/media/omx-plugin/hc/moz.build
index 513a554bfe9..d26e0e2bb10 100644
--- a/media/omx-plugin/hc/moz.build
+++ b/media/omx-plugin/hc/moz.build
@@ -20,3 +20,6 @@ LOCAL_INCLUDES += [
 
 # Don't use STL wrappers; this isn't Gecko code
 DISABLE_STL_WRAPPING = True
+
+# Suppress warnings in third-party code.
+CXXFLAGS += ['-Wno-multichar']
diff --git a/media/omx-plugin/kk/moz.build b/media/omx-plugin/kk/moz.build
index 183965dd9d1..051cc1d6bd2 100644
--- a/media/omx-plugin/kk/moz.build
+++ b/media/omx-plugin/kk/moz.build
@@ -20,3 +20,6 @@ LOCAL_INCLUDES += [
 
 # Don't use STL wrappers; this isn't Gecko code
 DISABLE_STL_WRAPPING = True
+
+# Suppress warnings in third-party code.
+CXXFLAGS += ['-Wno-multichar']