diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3241607cd..fbe631c30 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -118,7 +118,7 @@ if(APPLE)
   set(CMAKE_MACOSX_RPATH 0)
 endif(APPLE)
 
-if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Qunused-arguments -g")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Qunused-arguments -g")
 endif()
diff --git a/lib/config/CMakeLists.txt b/lib/config/CMakeLists.txt
index 09cd12830..102f6e6d1 100644
--- a/lib/config/CMakeLists.txt
+++ b/lib/config/CMakeLists.txt
@@ -24,7 +24,7 @@ set_property(SOURCE ${CMAKE_CURRENT_BINARY_DIR}/config_parser.cc PROPERTY EXCLUD
 flex_target(config_lexer config_lexer.ll ${CMAKE_CURRENT_BINARY_DIR}/config_lexer.cc)
 set_property(SOURCE ${CMAKE_CURRENT_BINARY_DIR}/config_lexer.cc PROPERTY EXCLUDE_UNITY_BUILD TRUE)
 
-if(APPLE)
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set_property(SOURCE ${CMAKE_CURRENT_BINARY_DIR}/config_parser.cc PROPERTY COMPILE_FLAGS "-Wno-deprecated-register")
   set_property(SOURCE ${CMAKE_CURRENT_BINARY_DIR}/config_lexer.cc PROPERTY COMPILE_FLAGS "-Wno-deprecated-register")
 endif()
diff --git a/tools/mkclass/CMakeLists.txt b/tools/mkclass/CMakeLists.txt
index 424d2d3ab..5dba4577a 100644
--- a/tools/mkclass/CMakeLists.txt
+++ b/tools/mkclass/CMakeLists.txt
@@ -22,7 +22,7 @@ bison_target(class_parser class_parser.yy ${CMAKE_CURRENT_BINARY_DIR}/class_pars
 flex_target(class_lexer class_lexer.ll ${CMAKE_CURRENT_BINARY_DIR}/class_lexer.cc)
 add_flex_bison_dependency(class_lexer class_parser)
 
-if(APPLE)
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set_property(SOURCE ${CMAKE_CURRENT_BINARY_DIR}/class_parser.cc PROPERTY COMPILE_FLAGS "-Wno-deprecated-register")
   set_property(SOURCE ${CMAKE_CURRENT_BINARY_DIR}/class_lexer.cc PROPERTY COMPILE_FLAGS "-Wno-deprecated-register")
 endif()