diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 0ffa4460..b1c61c49 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -50,8 +50,10 @@ jobs:
     - uses: actions/checkout@v3
     - name: Build tinydtls
       run: |
-        cmake -Dmake_tests=ON .
-        make
+        cmake -E make_directory build_test
+        cd build_test
+        cmake -DWARNING_TO_ERROR=ON -Dmake_tests=ON ..
+        cmake --build .
   build-macos-cmake:
     name: Build for macOS using CMake
     runs-on: macos-latest
@@ -60,8 +62,10 @@ jobs:
     - uses: actions/checkout@v3
     - name: Build tinydtls
       run: |
-        cmake -Dmake_tests=ON .
-        make
+        cmake -E make_directory build_test
+        cd build_test
+        cmake -DWARNING_TO_ERROR=ON -Dmake_tests=ON ..
+        cmake --build .
 
   build-windows:
     name: Build for Windows using CMake
@@ -71,6 +75,7 @@ jobs:
     - uses: actions/checkout@v3
     - name: Build tinydtls
       run: |
-        cmake -G "Unix Makefiles" .
-        make
-
+        cmake -E make_directory build_test
+        cd build_test
+        cmake -G "Unix Makefiles" -DWARNING_TO_ERROR=ON ..
+        cmake --build .
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 86762030..1292faf7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,6 +40,7 @@ set(SOVERSION "0" )
  
 option(DTLS_ECC "disable/enable support for TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8" ON )
 option(DTLS_PSK "disable/enable support for TLS_PSK_WITH_AES_128_CCM_8" ON)
+option(WARNING_TO_ERROR "force all compiler warnings to be errors" OFF)
 
 configure_file(dtls_config.h.cmake.in dtls_config.h )
 
@@ -67,8 +68,14 @@ target_compile_definitions(tinydtls PUBLIC DTLSv12 WITH_SHA256 SHA2_USE_INTTYPES
 if(CMAKE_GENERATOR MATCHES "Visual Studio")
     option(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS "Export all symbols when compiling to a .dll" ON)
     target_compile_options(tinydtls PRIVATE -Wall)
+    if(${WARNING_TO_ERROR})
+        target_compile_options(tinydtls PRIVATE -WX)
+     endif()
 elseif(NOT ZEPHYR_BASE)
     target_compile_options(tinydtls PRIVATE -fPIC -pedantic -std=c99 -Wall -Wextra -Wformat-security -Winline -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wunused)
+    if(${WARNING_TO_ERROR})
+        target_compile_options(tinydtls PRIVATE -Werror)
+    endif()
 endif()
 
 set_target_properties(tinydtls PROPERTIES VERSION ${PACKAGE_VERSION} SOVERSION ${SOVERSION})
@@ -83,6 +90,8 @@ else()
     install(TARGETS    tinydtls       DESTINATION ${CMAKE_INSTALL_LIBDIR} )
 endif()
 
-file(CONFIGURE OUTPUT .gitignore
-  NEWLINE_STYLE UNIX
-  CONTENT "*")
+if(NOT (${CMAKE_VERSION} VERSION_LESS "3.18.0"))
+    file(CONFIGURE OUTPUT .gitignore
+        NEWLINE_STYLE UNIX
+        CONTENT "*")
+endif()
diff --git a/dtls.c b/dtls.c
index 3479bf7e..dafb6121 100644
--- a/dtls.c
+++ b/dtls.c
@@ -246,7 +246,7 @@ memarray_init(&dtlscontext_storage, dtlscontext_storage_data,
  */
 #define CALL(Context, which, ...)					\
   ((Context)->h && (Context)->h->which					\
-   ? (Context)->h->which((Context), ##__VA_ARGS__)			\
+   ? (Context)->h->which((Context), __VA_ARGS__)			\
    : -1)
 
 static int
diff --git a/sha2/sha2.c b/sha2/sha2.c
index 633c3a91..9acec04c 100644
--- a/sha2/sha2.c
+++ b/sha2/sha2.c
@@ -224,6 +224,7 @@ static inline sha2_word64 get64be(const sha2_byte* data)
 #endif /* BYTE_ORDER != LITTLE_ENDIAN */
 }
 
+#if defined(WITH_SHA512) || (defined(WITH_SHA384) && BYTE_ORDER == LITTLE_ENDIAN)
 static inline void put64be(sha2_byte* data, sha2_word64 val)
 {
 #if BYTE_ORDER == LITTLE_ENDIAN
@@ -239,6 +240,7 @@ static inline void put64be(sha2_byte* data, sha2_word64 val)
 	MEMCPY_BCOPY(data, &val, sizeof(val));
 #endif /* BYTE_ORDER != LITTLE_ENDIAN */
 }
+#endif /* WITH_SHA512 || (WITH_SHA364 && BYTE_ORDER == LITTLE_ENDIAN) */
 
 /*
  * Macro for incrementally adding the unsigned 64-bit integer n to the
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index dc50bed8..06988ffd 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -25,13 +25,22 @@ project(tinydtls-tests)
 
 add_executable(dtls-server dtls-server.c)
 target_link_libraries(dtls-server LINK_PUBLIC tinydtls)
-target_compile_options(dtls-server PUBLIC -DTEST_INCLUDE -DDTLSv12 -DWITH_SHA256)
+target_compile_options(dtls-server PUBLIC -Wall -DTEST_INCLUDE -DDTLSv12 -DWITH_SHA256)
+if(${WARNING_TO_ERROR})
+    target_compile_options(dtls-server PUBLIC -Werror)
+endif()
 
 add_executable(ccm-test ccm-test.c)
 target_link_libraries(ccm-test LINK_PUBLIC tinydtls)
-target_compile_options(ccm-test PUBLIC -DTEST_INCLUDE -DDTLSv12 -DWITH_SHA256)
+target_compile_options(ccm-test PUBLIC -Wall -DTEST_INCLUDE -DDTLSv12 -DWITH_SHA256)
+if(${WARNING_TO_ERROR})
+    target_compile_options(ccm-test PUBLIC -Werror)
+endif()
 
 add_executable(dtls-client dtls-client.c)
 target_link_libraries(dtls-client LINK_PUBLIC tinydtls)
-target_compile_options(dtls-client PUBLIC -DTEST_INCLUDE -DDTLSv12 -DWITH_SHA256)
+target_compile_options(dtls-client PUBLIC -Wall -DTEST_INCLUDE -DDTLSv12 -DWITH_SHA256)
+if(${WARNING_TO_ERROR})
+    target_compile_options(dtls-client PUBLIC -Werror)
+endif()