diff --git a/src/Makevars b/src/Makevars
index 22145ed..32d998d 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -1,6 +1,6 @@
 PKG_CPPFLAGS = -I../inst/include \
 	-DRCPP_NO_RTTI \
-	-DRCPP_USE_UNWIND_PROTECT \
-	-mmacosx-version-min=10.13 -Werror=partial-availability
+	-DRCPP_USE_UNWIND_PROTECT
 
 CXX_STD = CXX17
+CXX = clang++ -mmacosx-version-min=10.13 -Werror=partial-availability