diff --git a/code/CMakeLists.txt b/code/CMakeLists.txt
index ba5415fe0..e05b4dd7b 100644
--- a/code/CMakeLists.txt
+++ b/code/CMakeLists.txt
@@ -1195,7 +1195,70 @@ TARGET_USE_COMMON_OUTPUT_DIRECTORY(assimp)
 IF (ASSIMP_WARNINGS_AS_ERRORS)
   MESSAGE(STATUS "Treating all warnings as errors (for assimp library only)")
   IF (MSVC)
-    TARGET_COMPILE_OPTIONS(assimp PRIVATE /W4 /WX)
+
+    IF(CMAKE_CXX_COMPILER_ID MATCHES "Clang" ) # clang-cl
+      TARGET_COMPILE_OPTIONS(assimp PRIVATE -Wall -Werror
+        -Wno-unused-function
+        -Wno-microsoft-enum-value
+        -Wno-switch-enum
+        -Wno-covered-switch-default
+        -Wno-reserved-identifier
+        -Wno-c++98-compat-pedantic
+        -Wno-c++98-compat
+        -Wno-documentation
+        -Wno-documentation-unknown-command
+        -Wno-deprecated-dynamic-exception-spec
+        -Wno-undef
+        -Wno-suggest-destructor-override
+        -Wno-suggest-override
+        -Wno-inconsistent-missing-destructor-override
+        -Wno-zero-as-null-pointer-constant
+        -Wno-global-constructors
+        -Wno-exit-time-destructors
+        -Wno-extra-semi-stmt
+        -Wno-missing-prototypes
+        -Wno-old-style-cast
+        -Wno-cast-align
+        -Wno-cast-qual
+        -Wno-float-equal
+        -Wno-implicit-int-float-conversion
+        -Wno-sign-conversion
+        -Wno-implicit-float-conversion
+        -Wno-implicit-int-conversion
+        -Wno-float-conversion
+        -Wno-double-promotion
+        -Wno-unused-macros
+        -Wno-disabled-macro-expansion
+        -Wno-shadow-field
+        -Wno-shadow
+        -Wno-language-extension-token
+        -Wno-header-hygiene
+        -Wno-tautological-value-range-compare
+        -Wno-tautological-type-limit-compare
+        -Wno-missing-noreturn
+        -Wno-missing-variable-declarations
+        -Wno-extra-semi
+        -Wno-nonportable-system-include-path
+        -Wno-undefined-reinterpret-cast
+        -Wno-shift-sign-overflow
+        -Wno-deprecated-copy-with-user-provided-dtor
+        -Wno-deprecated-copy-with-dtor
+        -Wno-deprecated
+        -Wno-format-nonliteral
+        -Wno-format-non-iso
+        -Wno-comma
+        -Wno-unreachable-code-break
+        -Wno-unreachable-code-return
+        -Wno-unreachable-code
+        -Wno-implicit-fallthrough
+        -Wno-unused-template
+        -Wno-undefined-func-template
+        -Wno-nested-anon-types
+        -Wno-declaration-after-statement
+      )
+    ELSE()
+      TARGET_COMPILE_OPTIONS(assimp PRIVATE /W4 /WX)
+    ENDIF()
   ELSE()
     TARGET_COMPILE_OPTIONS(assimp PRIVATE -Wall -Werror)
   ENDIF()
diff --git a/contrib/zlib/CMakeLists.txt b/contrib/zlib/CMakeLists.txt
index 469151ff6..5bc2d6065 100644
--- a/contrib/zlib/CMakeLists.txt
+++ b/contrib/zlib/CMakeLists.txt
@@ -76,7 +76,15 @@ if(MSVC)
     set(CMAKE_DEBUG_POSTFIX "d")
     add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
     add_definitions(-D_CRT_NONSTDC_NO_DEPRECATE)
+    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" ) # clang-cl
+        SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-deprecated-non-prototype")
+    endif()
+
     include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+else()
+    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" ) # clang-cl
+        SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-deprecated-non-prototype")
+    endif()
 endif()
 
 if(NOT CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_CURRENT_BINARY_DIR)
@@ -88,7 +96,7 @@ if(NOT CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_CURRENT_BINARY_DIR)
         message(STATUS "to 'zconf.h.included' because this file is included with zlib")
         message(STATUS "but CMake generates it automatically in the build directory.")
         file(RENAME ${CMAKE_CURRENT_SOURCE_DIR}/zconf.h ${CMAKE_CURRENT_SOURCE_DIR}/zconf.h.included)
-  endif()
+    endif()
 endif()
 
 set(ZLIB_PC ${CMAKE_CURRENT_BINARY_DIR}/zlib.pc)