diff --git a/CMakeLists.txt b/CMakeLists.txt
index 66f3fe5f0..608eae0cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -204,6 +204,9 @@ if(CMAKE_COMPILER_IS_CLANG)
     set(CMAKE_C_FLAGS_MEMSAN      "-fsanitize=memory -O3")
     set(CMAKE_C_FLAGS_MEMSANDBG   "-fsanitize=memory -O1 -g3 -fno-omit-frame-pointer -fno-optimize-sibling-calls -fsanitize-memory-track-origins=2")
     set(CMAKE_C_FLAGS_CHECK       "-Os")
+    if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 15)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-but-set-variable")
+    endif()
 endif(CMAKE_COMPILER_IS_CLANG)
 
 if(CMAKE_COMPILER_IS_IAR)
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 07599f5d1..e937bc366 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -170,7 +170,10 @@ if(CMAKE_COMPILER_IS_GNUCC)
 endif(CMAKE_COMPILER_IS_GNUCC)
 
 if(CMAKE_COMPILER_IS_CLANG)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wmissing-declarations -Wmissing-prototypes -Wdocumentation -Wno-documentation-deprecated-sync -Wunreachable-code")
+    if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 16)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wdocumentation")
+    endif()
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wmissing-declarations -Wmissing-prototypes -Wno-documentation-deprecated-sync -Wunreachable-code")
 endif(CMAKE_COMPILER_IS_CLANG)
 
 if(WIN32)