diff --git a/content/media/webrtc/LoadManagerFactory.cpp b/content/media/webrtc/LoadManagerFactory.cpp
index c49ecc226a2..abaeb875f92 100644
--- a/content/media/webrtc/LoadManagerFactory.cpp
+++ b/content/media/webrtc/LoadManagerFactory.cpp
@@ -15,6 +15,7 @@ LoadManager* LoadManagerBuild(void)
 {
   MOZ_ASSERT(NS_IsMainThread());
 
+#if defined(ANDROID) || defined(LINUX)
   int loadMeasurementInterval =
     mozilla::Preferences::GetInt("media.navigator.load_adapt.measure_interval", 1000);
   int averagingSeconds =
@@ -28,6 +29,10 @@ LoadManager* LoadManagerBuild(void)
                          averagingSeconds,
                          highLoadThreshold,
                          lowLoadThreshold);
+#else
+  // LoadManager not implemented on this platform.
+  return nullptr;
+#endif
 }
 
 void LoadManagerDestroy(mozilla::LoadManager* aLoadManager)
diff --git a/content/media/webrtc/LoadMonitor.cpp b/content/media/webrtc/LoadMonitor.cpp
index 0d77eaa294b..1d7d83429c4 100644
--- a/content/media/webrtc/LoadMonitor.cpp
+++ b/content/media/webrtc/LoadMonitor.cpp
@@ -23,7 +23,7 @@
 #include "mozilla/TimeStamp.h"
 #include "mozilla/Services.h"
 
-#if defined(ANDROID) || defined(LINUX) || defined(XP_MACOSX)
+#if defined(ANDROID) || defined(LINUX)
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <unistd.h>
@@ -180,7 +180,7 @@ private:
 LoadInfo::LoadInfo(int aLoadUpdateInterval)
   : mLoadUpdateInterval(aLoadUpdateInterval)
 {
-#if defined(ANDROID) || defined(LINUX) || defined(XP_MACOSX)
+#if defined(ANDROID) || defined(LINUX)
   mTicksPerInterval = (sysconf(_SC_CLK_TCK) * mLoadUpdateInterval) / 1000;
 #endif
 }
diff --git a/content/media/webrtc/moz.build b/content/media/webrtc/moz.build
index a1c73cb62a1..cf2599a1143 100644
--- a/content/media/webrtc/moz.build
+++ b/content/media/webrtc/moz.build
@@ -17,13 +17,16 @@ if CONFIG['MOZ_WEBRTC']:
                 'LoadMonitor.h',
                 'MediaEngineWebRTC.h']
     UNIFIED_SOURCES += [
-        'LoadManager.cpp',
         'LoadManagerFactory.cpp',
-        'LoadMonitor.cpp',
         'MediaEngineTabVideoSource.cpp',
         'MediaEngineWebRTCAudio.cpp',
         'MediaEngineWebRTCVideo.cpp',
     ]
+    if CONFIG['OS_ARCH'] == 'Android' or CONFIG['OS_ARCH'] == 'Linux':
+        UNIFIED_SOURCES += [
+            'LoadManager.cpp',
+            'LoadMonitor.cpp',
+        ]
     # MediaEngineWebRTC.cpp needs to be built separately.
     SOURCES += [
         'MediaEngineWebRTC.cpp',