diff --git a/dom/plugins/ipc/PluginInstanceChild.cpp b/dom/plugins/ipc/PluginInstanceChild.cpp
index 36bf4c048c7..bab56a20413 100644
--- a/dom/plugins/ipc/PluginInstanceChild.cpp
+++ b/dom/plugins/ipc/PluginInstanceChild.cpp
@@ -130,7 +130,7 @@ PluginInstanceChild::PluginInstanceChild(const NPPluginFuncs* aPluginIface,
     , mMode(aMode)
     , mNames(aNames)
     , mValues(aValues)
-#if defined(XP_MACOSX)
+#if defined(XP_DARWIN)
     , mContentsScaleFactor(1.0)
 #endif
     , mDrawingModel(kDefaultDrawingModel)
@@ -1281,6 +1281,8 @@ PluginInstanceChild::AnswerNPP_SetWindow(const NPRemoteWindow& aWindow)
     // TODO: Need Android impl
 #elif defined(MOZ_WIDGET_QT)
     // TODO: Need QT-nonX impl
+#elif defined(MOZ_WIDGET_UIKIT)
+    // Don't care
 #else
 #  error Implement me for your OS
 #endif
@@ -2933,7 +2935,7 @@ PluginInstanceChild::MaybeCreatePlatformHelperSurface(void)
 bool
 PluginInstanceChild::EnsureCurrentBuffer(void)
 {
-#ifndef XP_MACOSX
+#ifndef XP_DARWIN
     nsIntRect toInvalidate(0, 0, 0, 0);
     gfxIntSize winSize = gfxIntSize(mWindow.width, mWindow.height);
 
@@ -2979,7 +2981,7 @@ PluginInstanceChild::EnsureCurrentBuffer(void)
     }
 
     return true;
-#else // XP_MACOSX
+#elif defined(XP_MACOSX)
 
     if (!mDoubleBufferCARenderer.HasCALayer()) {
         void *caLayer = nullptr;
@@ -3033,9 +3035,8 @@ PluginInstanceChild::EnsureCurrentBuffer(void)
         nsIntRect toInvalidate(0, 0, mWindow.width, mWindow.height);
         mAccumulatedInvalidRect.UnionRect(mAccumulatedInvalidRect, toInvalidate);
     }
-  
-    return true;
 #endif
+    return true;
 }
 
 void
diff --git a/dom/plugins/ipc/PluginInstanceChild.h b/dom/plugins/ipc/PluginInstanceChild.h
index 2fe6d4c16f4..c3300dcd08a 100644
--- a/dom/plugins/ipc/PluginInstanceChild.h
+++ b/dom/plugins/ipc/PluginInstanceChild.h
@@ -374,7 +374,7 @@ private:
     InfallibleTArray<nsCString> mValues;
     NPP_t mData;
     NPWindow mWindow;
-#if defined(XP_MACOSX)
+#if defined(XP_DARWIN)
     double mContentsScaleFactor;
 #endif
     int16_t               mDrawingModel;
diff --git a/dom/plugins/ipc/PluginInstanceParent.cpp b/dom/plugins/ipc/PluginInstanceParent.cpp
index 8cc92e6233e..fc8e9c536a0 100644
--- a/dom/plugins/ipc/PluginInstanceParent.cpp
+++ b/dom/plugins/ipc/PluginInstanceParent.cpp
@@ -270,7 +270,7 @@ PluginInstanceParent::AnswerNPN_GetValue_NPNVnetscapeWindow(NativeWindowHandle*
     HWND id;
 #elif defined(MOZ_X11)
     XID id;
-#elif defined(XP_MACOSX)
+#elif defined(XP_DARWIN)
     intptr_t id;
 #elif defined(ANDROID)
     // TODO: Need Android impl
diff --git a/dom/plugins/ipc/PluginModuleChild.cpp b/dom/plugins/ipc/PluginModuleChild.cpp
index e24bcdd367e..6cd941fd004 100644
--- a/dom/plugins/ipc/PluginModuleChild.cpp
+++ b/dom/plugins/ipc/PluginModuleChild.cpp
@@ -280,7 +280,7 @@ PluginModuleChild::InitForChrome(const std::string& aPluginFilename,
 
     nsPluginFile pluginFile(localFile);
 
-#if defined(MOZ_X11) || defined(OS_MACOSX)
+#if defined(MOZ_X11) || defined(XP_MACOSX)
     nsPluginInfo info = nsPluginInfo();
     if (NS_FAILED(pluginFile.GetPluginInfo(info, &mLibrary))) {
         return false;
@@ -291,7 +291,7 @@ PluginModuleChild::InitForChrome(const std::string& aPluginFilename,
     if (StringBeginsWith(nsDependentCString(info.fDescription), flash10Head)) {
         AddQuirk(QUIRK_FLASH_EXPOSE_COORD_TRANSLATION);
     }
-#else // defined(OS_MACOSX)
+#else // defined(XP_MACOSX)
     const char* namePrefix = "Plugin Content";
     char nameBuffer[80];
     snprintf(nameBuffer, sizeof(nameBuffer), "%s (%s)", namePrefix, info.fName);