diff --git a/GNUmakefile b/GNUmakefile
index f0dc5441..548fe2bf 100755
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -483,7 +483,7 @@ ifeq ($(IS_ARMV8),1)
 
   TPROG = TestPrograms/test_arm_asimd.cxx
   TOPT = -march=armv8-a
-  HAVE_OPT = $(shell $(CXX) $(CXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
+  HAVE_OPT = $(shell $(CXX) $(TCXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
   ifeq ($(strip $(HAVE_OPT)),0)
     ASIMD_FLAG = -march=armv8-a
     ARIA_FLAG = -march=armv8-a
@@ -506,7 +506,7 @@ ifeq ($(IS_ARMV8),1)
   ifneq ($(ASIMD_FLAG),)
     TPROG = TestPrograms/test_arm_crc.cxx
     TOPT = -march=armv8-a+crc
-    HAVE_OPT = $(shell $(CXX) $(CXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
+    HAVE_OPT = $(shell $(CXX) $(TCXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
     ifeq ($(strip $(HAVE_OPT)),0)
       CRC_FLAG = -march=armv8-a+crc
     else
@@ -515,7 +515,7 @@ ifeq ($(IS_ARMV8),1)
 
     TPROG = TestPrograms/test_arm_aes.cxx
     TOPT = -march=armv8-a+crypto
-    HAVE_OPT = $(shell $(CXX) $(CXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
+    HAVE_OPT = $(shell $(CXX) $(TCXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
     ifeq ($(strip $(HAVE_OPT)),0)
       AES_FLAG = -march=armv8-a+crypto
     else
@@ -524,7 +524,7 @@ ifeq ($(IS_ARMV8),1)
 
     TPROG = TestPrograms/test_arm_pmull.cxx
     TOPT = -march=armv8-a+crypto
-    HAVE_OPT = $(shell $(CXX) $(CXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
+    HAVE_OPT = $(shell $(CXX) $(TCXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
     ifeq ($(strip $(HAVE_OPT)),0)
       GCM_FLAG = -march=armv8-a+crypto
       GF2N_FLAG = -march=armv8-a+crypto
@@ -534,7 +534,7 @@ ifeq ($(IS_ARMV8),1)
 
     TPROG = TestPrograms/test_arm_sha.cxx
     TOPT = -march=armv8-a+crypto
-    HAVE_OPT = $(shell $(CXX) $(CXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
+    HAVE_OPT = $(shell $(CXX) $(TCXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
     ifeq ($(strip $(HAVE_OPT)),0)
       SHA_FLAG = -march=armv8-a+crypto
     else
@@ -543,7 +543,7 @@ ifeq ($(IS_ARMV8),1)
 
     TPROG = TestPrograms/test_arm_sm3.cxx
     TOPT = -march=armv8.4-a+crypto
-    HAVE_OPT = $(shell $(CXX) $(CXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
+    HAVE_OPT = $(shell $(CXX) $(TCXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
     ifeq ($(strip $(HAVE_OPT)),0)
       SM3_FLAG = -march=armv8.4-a+crypto
       SM4_FLAG = -march=armv8.4-a+crypto
@@ -551,7 +551,7 @@ ifeq ($(IS_ARMV8),1)
 
     TPROG = TestPrograms/test_arm_sha3.cxx
     TOPT = -march=armv8.4-a+crypto
-    HAVE_OPT = $(shell $(CXX) $(CXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
+    HAVE_OPT = $(shell $(CXX) $(TCXXFLAGS) $(ACLE_FLAG) $(ZOPT) $(TOPT) $(TPROG) -o $(TOUT) 2>&1 | tr ' ' '\n' | wc -l)
     ifeq ($(strip $(HAVE_OPT)),0)
       SHA3_FLAG = -march=armv8.4-a+crypto
     endif