diff --git a/dom/media/MediaDecoderStateMachine.cpp b/dom/media/MediaDecoderStateMachine.cpp
index 9679e045d6d0..f45f308a76dc 100644
--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -18,6 +18,7 @@
 #include "nsTArray.h"
 #include "MediaDecoder.h"
 #include "MediaDecoderReader.h"
+#include "mozilla/MathAlgorithms.h"
 #include "mozilla/mozalloc.h"
 #include "VideoUtils.h"
 #include "mozilla/dom/TimeRanges.h"
@@ -165,7 +166,7 @@ static_assert(QUICK_BUFFERING_LOW_DATA_USECS <= AMPLE_AUDIO_USECS,
 // MediaDecoderStateMachine::UpdateEstimatedDuration(); changes of duration
 // less than this are ignored, as they're assumed to be the result of
 // instability in the duration estimation.
-static const int64_t ESTIMATED_DURATION_FUZZ_FACTOR_USECS = USECS_PER_S / 2;
+static const uint64_t ESTIMATED_DURATION_FUZZ_FACTOR_USECS = USECS_PER_S / 2;
 
 static TimeDuration UsecsToDuration(int64_t aUsecs) {
   return TimeDuration::FromMicroseconds(aUsecs);
@@ -1449,7 +1450,7 @@ void MediaDecoderStateMachine::UpdateEstimatedDuration(int64_t aDuration)
   AssertCurrentThreadInMonitor();
   int64_t duration = GetDuration();
   if (aDuration != duration &&
-      std::abs(aDuration - duration) > ESTIMATED_DURATION_FUZZ_FACTOR_USECS) {
+      mozilla::Abs(aDuration - duration) > ESTIMATED_DURATION_FUZZ_FACTOR_USECS) {
     SetDuration(aDuration);
     nsCOMPtr<nsIRunnable> event =
       NS_NewRunnableMethod(mDecoder, &MediaDecoder::DurationChanged);