diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 6859e27c3..3405e85d4 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -166,7 +166,7 @@ set(SRB2_CORE_GAME_SOURCES
 	p_tick.h
 )
 
-if(NOT CLANG)
+if(NOT (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
 	set(SRB2_CORE_SOURCES ${SRB2_CORE_SOURCES} string.c)
 endif()
 
@@ -404,7 +404,7 @@ endif()
 
 # Compatibility flag with later versions of GCC
 # We should really fix our code to not need this
-if(NOT CLANG AND NOT MSVC)
+if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
 	set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} -mno-ms-bitfields)
 endif()
 
@@ -429,4 +429,4 @@ endif()
 
 if(NOT ${SRB2_SDL2_AVAILABLE} AND NOT ${SRB2_WIN32_AVAILABLE})
 	message(FATAL_ERROR "There are no targets available to build an SRB2 executable. :(")
-endif()
\ No newline at end of file
+endif()
diff --git a/src/sdl/CMakeLists.txt b/src/sdl/CMakeLists.txt
index b3fa5390c..eb832797e 100644
--- a/src/sdl/CMakeLists.txt
+++ b/src/sdl/CMakeLists.txt
@@ -117,7 +117,7 @@ if(${SDL2_FOUND})
 	add_executable(SRB2SDL2 MACOSX_BUNDLE WIN32 ${SRB2_SDL2_TOTAL_SOURCES})
 	set_target_properties(SRB2SDL2 PROPERTIES OUTPUT_NAME ${SRB2_SDL2_EXE_NAME})
 
-	if(CLANG)
+	if((CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang"))
 		add_framework(CoreFoundation SRB2SDL2)
 		add_framework(SDL2 SRB2SDL2)
 		add_framework(SDL2_mixer SRB2SDL2)
@@ -224,7 +224,7 @@ if(${SDL2_FOUND})
 	endif()
 
 	#### Installation ####
-	if (CLANG)
+	if (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
 		install(TARGETS SRB2SDL2
 			BUNDLE DESTINATION .
 		)
@@ -265,7 +265,7 @@ if(${SDL2_FOUND})
 
 
 	# Mac bundle fixup
-	if(CLANG)
+	if (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
 		install(CODE "
 			include(BundleUtilities)
 			fixup_bundle(\"${CMAKE_INSTALL_PREFIX}/Sonic Robo Blast 2.app\"
@@ -279,4 +279,4 @@ if(${SDL2_FOUND})
 else()
 	message(WARNING "SDL2 was not found, so the SDL2 target will not be available.")
 	set(SRB2_SDL2_AVAILABLE NO PARENT_SCOPE)
-endif()
\ No newline at end of file
+endif()