diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
index b5f96e8f711..ca07c5c3618 100644
--- a/cmake/modules/HandleLLVMOptions.cmake
+++ b/cmake/modules/HandleLLVMOptions.cmake
@@ -3,6 +3,7 @@
 # selections.
 
 include(AddLLVMDefinitions)
+include(CheckCCompilerFlag)
 
 if( CMAKE_COMPILER_IS_GNUCXX )
   set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
@@ -194,9 +195,13 @@ elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
     if (LLVM_ENABLE_PEDANTIC)
       add_llvm_definitions( -pedantic -Wno-long-long )
     endif (LLVM_ENABLE_PEDANTIC)
-    check_cxx_compiler_flag("-Werror -Wcovered-switch-default" SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
-    if( SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG )
-      add_llvm_definitions( -Wcovered-switch-default )
+    check_cxx_compiler_flag("-Werror -Wcovered-switch-default" CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
+    if( CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG )
+      set( CMAKE_CXX_FlAGS "${CMAKE_CXX_FLAGS} -Wcovered-switch-default" )
+    endif()
+    check_c_compiler_flag("-Werror -Wcovered-switch-default" C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
+    if( C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG )
+      set( CMAKE_C_FlAGS "${CMAKE_C_FLAGS} -Wcovered-switch-default" )
     endif()
   endif (LLVM_ENABLE_WARNINGS)
   if (LLVM_ENABLE_WERROR)