diff --git a/tools/mmp/Makefile b/tools/mmp/Makefile
index 511746c31c..2e220de978 100644
--- a/tools/mmp/Makefile
+++ b/tools/mmp/Makefile
@@ -68,7 +68,7 @@ Xamarin.Mac.registrar.full.x86_64.m:   $(TOP)/src/build/mac/full-64/Xamarin.Mac.
 	$(Q) touch Xamarin.Mac.registrar.full.x86_64.m Xamarin.Mac.registrar.full.x86_64.h
 
 Xamarin.Mac.registrar.%.i386.a:   Xamarin.Mac.registrar.%.i386.m
-	$(Q_CC) xcrun -sdk macosx clang -DDEBUG -DOBJC_OLD_DISPATCH_PROTOTYPES=1 -g -gdwarf-2 -x objective-c++ -stdlib=libc++ -o $@ -c -arch i386 $< -Wall -Wno-unguarded-availability-new -I$(MAC_DESTDIR)$(MAC_FRAMEWORK_CURRENT_DIR)/include -mmacosx-version-min=$(MIN_OSX_SDK_VERSION)
+	$(Q_CC) $(MAC32_CXX) -DDEBUG -DOBJC_OLD_DISPATCH_PROTOTYPES=1 -g -gdwarf-2 -x objective-c++ -stdlib=libc++ -o $@ -c -arch i386 $< -Wall -Wno-unguarded-availability-new -I$(MAC_DESTDIR)$(MAC_FRAMEWORK_CURRENT_DIR)/include -mmacosx-version-min=$(MIN_OSX_SDK_VERSION)
 
 Xamarin.Mac.registrar.%.x86_64.a: Xamarin.Mac.registrar.%.x86_64.m
 	$(Q_CC) xcrun -sdk macosx clang -DDEBUG -DOBJC_OLD_DISPATCH_PROTOTYPES=1 -g -gdwarf-2 -x objective-c++ -stdlib=libc++ -o $@ -c -arch x86_64 $< -Wall -Wno-unguarded-availability-new -I$(MAC_DESTDIR)$(MAC_FRAMEWORK_CURRENT_DIR)/include -mmacosx-version-min=$(MIN_OSX_SDK_VERSION) -fobjc-runtime=macosx