diff --git a/test/gpu/native/interop/gpuLibrary/Makefile b/test/gpu/native/interop/gpuLibrary/Makefile
index 3114fc2dab5b..d02a9b682cc3 100644
--- a/test/gpu/native/interop/gpuLibrary/Makefile
+++ b/test/gpu/native/interop/gpuLibrary/Makefile
@@ -1,10 +1,10 @@
 include lib/Makefile.udf2
 test_udf2_make_cpu: test_udf2.cpp lib/libudf2.a
-	@$(CHPL_COMPILER) -x c++ -lstdc++ $(CHPL_CFLAGS) -o test_udf2_make $< $(CHPL_LDFLAGS)
+	@$(CHPL_COMPILER) -x c++ -lstdc++ $(CXXFLAGS) $(CHPL_CFLAGS) -o test_udf2_make $< $(CHPL_LDFLAGS)
 
 test_udf2_make_nvidia: test_udf2.cpp lib/libudf2.a
-	@$(CHPL_COMPILER) -x cuda -lstdc++ $(CHPL_CFLAGS) -o test_udf2_make $< $(CHPL_LDFLAGS)
+	@$(CHPL_COMPILER) -x cuda -lstdc++ $(CXXFLAGS) $(CHPL_CFLAGS) -o test_udf2_make $< $(CHPL_LDFLAGS)
 
 test_udf2_make_amd: test_udf2.cpp lib/libudf2.a
-	@$(CHPL_COMPILER) -x hip -lstdc++ $(CHPL_CFLAGS) -o test_udf2_make $< $(CHPL_LDFLAGS)
+	@$(CHPL_COMPILER) -x hip -lstdc++ $(CXXFLAGS) $(CHPL_CFLAGS) -o test_udf2_make $< $(CHPL_LDFLAGS)
 
diff --git a/test/gpu/native/interop/gpuLibrary/udf2.prediff b/test/gpu/native/interop/gpuLibrary/udf2.prediff
index 4b79ef2bb4a6..e3dfd738b27f 100755
--- a/test/gpu/native/interop/gpuLibrary/udf2.prediff
+++ b/test/gpu/native/interop/gpuLibrary/udf2.prediff
@@ -14,7 +14,7 @@ if [[ "$chpl_gpu" == "nvidia" ]]; then
 elif [[ "$chpl_gpu" == "amd" ]]; then
   gpu_flags="-x hip"
 fi
-$cxx $gpu_flags test_udf2.cpp -Ilib -Llib/ -ludf2 $libs -o test_udf2_compileline
+$cxx $CXXFLAGS $gpu_flags test_udf2.cpp -Ilib -Llib/ -ludf2 $libs -o test_udf2_compileline
 echo "Running test_udf2_compileline" >> $OUTFILE
 ./test_udf2_compileline >> $OUTFILE