--- a/build/macosx/mozconfig.common
+++ b/build/macosx/mozconfig.common
@@ -1,9 +1,7 @@
 if test `uname -s` = Linux; then
   . $topsrcdir/build/macosx/cross-mozconfig.common
 else
   . $topsrcdir/build/macosx/local-mozconfig.common
 fi
 
-# Enable stylo in automation builds.
-# Can be removed after bug 1375774 is resolved.
-ac_add_options --enable-stylo=build
+. $topsrcdir/build/mozconfig.stylo

--- a/build/mozconfig.common
+++ b/build/mozconfig.common
@@ -9,19 +9,16 @@
 # architectures, though note that if you want to override options set in
 # another mozconfig file, you'll need to use mozconfig.common.override instead
 # of this file.
 
 mk_add_options AUTOCLOBBER=1
 
 ac_add_options --enable-crashreporter
 
-# Tell the build system where to find llvm-config for builds on automation.
-export LLVM_CONFIG="${TOOLTOOL_DIR:-$topsrcdir}/clang/bin/llvm-config"
-
 # Enable checking that add-ons are signed by the trusted root
 MOZ_ADDON_SIGNING=${MOZ_ADDON_SIGNING-1}
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_SIGNING=${MOZ_REQUIRE_SIGNING-0}
 
 ac_add_options --enable-js-shell
 
 . "$topsrcdir/build/mozconfig.automation"

new file mode 100644
--- /dev/null
+++ b/build/mozconfig.stylo
@@ -0,0 +1,6 @@
+# Tell the build system where to find llvm-config for builds on automation.
+export LLVM_CONFIG="${TOOLTOOL_DIR:-$topsrcdir}/clang/bin/llvm-config"
+
+# TODO remove once configure defaults to stylo once stylo enabled
+# on all platforms.
+ac_add_options --enable-stylo=build