diff --git a/GNUmakefile b/GNUmakefile
index 753fb05c10..6f7c1e7e13 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -12,7 +12,7 @@ ifdef CONFIG
 		-DFACTOR_GIT_LABEL="$(GIT_LABEL)" \
 		$(SITE_CFLAGS)
 
-	CXXFLAGS += -std=c++11
+	CXXFLAGS += -std=c++11 -stdlib=libc++
 
 	ifdef DEBUG
 		CFLAGS += -g -DFACTOR_DEBUG
diff --git a/vm/Config.macosx b/vm/Config.macosx
index c2b3e38f70..74f4fcacef 100644
--- a/vm/Config.macosx
+++ b/vm/Config.macosx
@@ -1,6 +1,6 @@
 include vm/Config.unix
 #SITE_CFLAGS +=
-SITE_CFLAGS += -mmacosx-version-min=10.5
+SITE_CFLAGS += -mmacosx-version-min=10.9
 
 PLAF_DLL_OBJS += vm/os-macosx.o vm/mach_signal.o vm/mvm-unix.o
 PLAF_MASTER_HEADERS += vm/os-macosx.hpp vm/mach_signal.hpp