diff --git a/appveyor.yml b/appveyor.yml
index 655f2be2..0c6f6a21 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -11,6 +11,18 @@ image:
 - Visual Studio 2019
 - Visual Studio 2017
 - Visual Studio 2015
+environment:
+  matrix:
+  - LTC_CC: cl
+  - LTC_CC: clang-cl
+matrix:
+  exclude:
+  - image: Visual Studio 2019
+    LTC_CC: clang-cl
+  - image: Visual Studio 2017
+    LTC_CC: clang-cl
+  - image: Visual Studio 2015
+    LTC_CC: clang-cl
 build_script:
 - cmd: >-
     if "Visual Studio 2022"=="%APPVEYOR_BUILD_WORKER_IMAGE%" call "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvars64.bat"
@@ -18,6 +30,8 @@ build_script:
       if "Visual Studio 2017"=="%APPVEYOR_BUILD_WORKER_IMAGE%" call "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvars64.bat"
       if "Visual Studio 2015"=="%APPVEYOR_BUILD_WORKER_IMAGE%" call "C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\SetEnv.cmd" /x64
       if "Visual Studio 2015"=="%APPVEYOR_BUILD_WORKER_IMAGE%" call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" x86_amd64
+      if "clang-cl"=="%LTC_CC%" set "PATH=C:\Program Files\LLVM\bin;C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\Llvm\x64\bin;%PATH%"
+      if "clang-cl"=="%LTC_CC%" clang-cl --version
       cd..
       git clone https://github.com/libtom/libtommath.git --branch=master
       cp libtomcrypt\.ci\cmake.bat libtommath\cmake.bat
@@ -27,11 +41,11 @@ build_script:
       cd..
       cd libtomcrypt
       .ci\cmake.bat
-      nmake -f makefile.msvc all
+      nmake -f makefile.msvc all CC=%LTC_CC%
       cp test.exe test-stock.exe
       cp timing.exe timing-stock.exe
       nmake -f makefile.msvc clean
-      nmake -f makefile.msvc all CFLAGS="/Ox /DUSE_LTM /DLTM_DESC /DLTC_NO_ACCEL /I../libtommath"
+      nmake -f makefile.msvc all CC=%LTC_CC% CFLAGS="/Ox /DUSE_LTM /DLTM_DESC /DLTC_NO_ACCEL /I../libtommath"
 test_script:
 - cmd: >-
     test-stock.exe
diff --git a/makefile.msvc b/makefile.msvc
index a9ae2b9d..763896cc 100644
--- a/makefile.msvc
+++ b/makefile.msvc
@@ -287,25 +287,25 @@ $(LIBMAIN_S): $(OBJECTS)
 
 #Demo tools/utilities
 hashsum.exe: demos/hashsum.c tests/common.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/hashsum.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/hashsum.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 crypt.exe: demos/crypt.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/crypt.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/crypt.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 small.exe: demos/small.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/small.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/small.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 tv_gen.exe: demos/tv_gen.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/tv_gen.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/tv_gen.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 sizes.exe: demos/sizes.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/sizes.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/sizes.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 constants.exe: demos/constants.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/constants.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/constants.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 timing.exe: demos/timing.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/timing.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/timing.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 der_print_flexi.exe: demos/der_print_flexi.c $(LIBMAIN_S)
-	cl $(LTC_CFLAGS) demos/der_print_flexi.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) demos/der_print_flexi.c tests/common.c $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 
 #Tests
 test.exe: $(LIBMAIN_S) $(TOBJECTS)
-	cl $(LTC_CFLAGS) $(TOBJECTS) $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
+	$(CC) $(LTC_CFLAGS) $(TOBJECTS) $(LIBMAIN_S) $(LTC_LDFLAGS) /Fe$@
 	@echo NOTICE: start the tests by launching test.exe
 
 ALL_TEST=hashsum.exe crypt.exe small.exe tv_gen.exe sizes.exe constants.exe timing.exe test.exe