diff --git a/build/config/BUILDCONFIG.gn b/build/config/BUILDCONFIG.gn
index 9e38ee0e592b..bd54ce154b13 100644
--- a/build/config/BUILDCONFIG.gn
+++ b/build/config/BUILDCONFIG.gn
@@ -123,6 +123,9 @@ if (current_os == "") {
 #   even if the value is overridden, which is wasteful. See first bullet.
 
 declare_args() {
+  is_electron_build = false
+  is_mas_build = false
+
   # Set to enable the official build level of optimization. This has nothing
   # to do with branding, but enables an additional level of optimization above
   # release (!is_debug). This might be better expressed as a tri-state
@@ -539,6 +542,7 @@ default_compiler_configs = [
   "//build/config/compiler:thin_archive",
   "//build/config/coverage:default_coverage",
   "//build/config/sanitizers:default_sanitizer_flags",
+  "//electron/build/config:mas_build",
 ]
 
 if (is_win) {
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 9a10137aa405..bb33e5450eaa 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -579,10 +579,13 @@ config("compiler") {
       ldflags += [ "-Wl,--lto-O0" ]
     }
 
-    cflags += [ "-fwhole-program-vtables" ]
-    if (!is_win) {
-      ldflags += [ "-fwhole-program-vtables" ]
-    }
+    # -fwhole-program-vtables doesn't work well in Electron right now, as it's
+    # not a single binary and the optimizations break interfaces used across
+    # binary boundaries.
+    # cflags += [ "-fwhole-program-vtables" ]
+    # if (!is_win) {
+    #  ldflags += [ "-fwhole-program-vtables" ]
+    #}
 
     # Work-around for http://openradar.appspot.com/20356002
     if (is_mac) {