--- a/mail/app/moz.build
+++ b/mail/app/moz.build
@@ -5,16 +5,17 @@
 
 DIRS += ['profile']
 
 GeckoProgram(CONFIG['MOZ_APP_NAME'])
 USE_LIBS += ['mozglue']
 SOURCES += ['nsMailApp.cpp']
 LOCAL_INCLUDES += [
     '!/build',
+    '/%s/ipc/contentproc/' % CONFIG['mozreltopsrcdir'],
     '/%s/toolkit/xre' % CONFIG['mozreltopsrcdir'],
     '/%s/xpcom/base' % CONFIG['mozreltopsrcdir'],
     '/%s/xpcom/build' % CONFIG['mozreltopsrcdir'],
 ]
 
 if CONFIG['LIBFUZZER']:
     USE_LIBS += [ 'fuzzer' ]
     LOCAL_INCLUDES += [

--- a/mail/app/nsMailApp.cpp
+++ b/mail/app/nsMailApp.cpp
@@ -84,17 +84,17 @@ SSE2Check()
                    MOZ_ARRAY_LENGTH(sSSE2Message) - 1));
   // _exit() instead of exit() to avoid running the usual "at exit" code.
   _exit(255);
 }
 #endif
 
 #if !defined(MOZ_WIDGET_COCOA) && !defined(MOZ_WIDGET_ANDROID)
 #define MOZ_BROWSER_CAN_BE_CONTENTPROC
-#include "../../mozilla/ipc/contentproc/plugin-container.cpp"
+#include "plugin-container.cpp"
 #endif
 
 using namespace mozilla;
 
 #ifdef XP_MACOSX
 #define kOSXResourcesFolder "Resources"
 #endif
 #define kDesktopFolder ""