diff --git a/Makefile.config b/Makefile.config
index a119be7d2..3613a3c7e 100644
--- a/Makefile.config
+++ b/Makefile.config
@@ -110,6 +110,9 @@ CLANG_DEPS_NO_MODELS = $(INFER_BIN)
 CLANG_DEPS = $(CLANG_DEPS_NO_MODELS) $(MODELS_RESULTS_FILE)
 
 XCODE_ISYSROOT_SUFFIX = Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk
+ifeq ($(wildcard $(XCODE_BASE)/$(XCODE_ISYSROOT_SUFFIX)),)
+  XCODE_ISYSROOT_SUFFIX = SDKs/MacOSX.sdk
+endif
 
 ifeq ($(HAS_OBJC),yes)
 XCODE_ISYSROOT = $(XCODE_BASE)/$(XCODE_ISYSROOT_SUFFIX)
diff --git a/facebook-clang-plugins/Makefile.config b/facebook-clang-plugins/Makefile.config
index 8e9902988..b75513707 100644
--- a/facebook-clang-plugins/Makefile.config
+++ b/facebook-clang-plugins/Makefile.config
@@ -41,6 +41,9 @@ OCAML_CPP?=$(LOCAL_CLANG) -cc1 -E -P -x c -main-file-name - -o -
 
 # Which SDK to use (if any)
 SDKPATH?=$(shell ls -d "`xcode-select --print-path 2> /dev/null`"/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator*.sdk 2> /dev/null | sort -r | head -n 1 || true)
+ifeq ($SDKPATH,)
+  SDKPATH?=$(shell ls -d "`xcode-select --print-path 2> /dev/null`"/SDKs/MacOSX.sdk 2> /dev/null | sort -r | head -n 1 || true)
+endif
 
 ifeq ($(SDKPATH),)
 HAS_OBJC=no