diff --git a/Makefile b/Makefile
index 7baff751c..5b3f5fdf7 100644
--- a/Makefile
+++ b/Makefile
@@ -112,7 +112,7 @@ CMAKE_PARAMS = -DZSTD_BUILD_CONTRIB:BOOL=ON -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_B
 list:
 	@$(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | sort | egrep -v -e '^[^[:alnum:]]' -e '^$@$$' | xargs
 
-.PHONY: install clangtest gpptest armtest usan asan uasan
+.PHONY: install clangtest armtest usan asan uasan
 install:
 	@$(MAKE) -C $(ZSTDDIR) $@
 	@$(MAKE) -C $(PRGDIR) $@
@@ -179,8 +179,10 @@ ppcfuzz: clean
 ppc64fuzz: clean
 	CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static MOREFLAGS="-m64 -static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest
 
-gpptest: clean
-	CC=$(CXX) $(MAKE) -C $(PRGDIR) all CFLAGS="-O3 -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror"
+.PHONY: cxxtest
+cxxtest: CXXFLAGS += -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror
+cxxtest: clean
+	$(MAKE) -C $(PRGDIR) all CC="$(CXX) -Wno-deprecated" CFLAGS="$(CXXFLAGS)"   # adding -Wno-deprecated to avoid clang++ warning on dealing with C files directly
 
 gcc5test: clean
 	gcc-5 -v