diff --git a/ntoskrnl/CMakeLists.txt b/ntoskrnl/CMakeLists.txt
index 6849bcf0099..a359482aad8 100644
--- a/ntoskrnl/CMakeLists.txt
+++ b/ntoskrnl/CMakeLists.txt
@@ -28,7 +28,7 @@ endif()
 
 add_asm_files(ntoskrnl_asm ${NTOSKRNL_ASM_SOURCE})
 
-if (GCC AND CLANG)
+if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
     # Clang optimises strcmp calls to memcmp.
     target_sources(libntoskrnl PRIVATE $<TARGET_OBJECTS:memcmp>)
 endif()
diff --git a/sdk/cmake/msvc.cmake b/sdk/cmake/msvc.cmake
index f32f88cf786..139a886f30f 100644
--- a/sdk/cmake/msvc.cmake
+++ b/sdk/cmake/msvc.cmake
@@ -1,6 +1,10 @@
 
 if(CMAKE_BUILD_TYPE STREQUAL "Release")
-    add_compile_options(/Ox /Ob2 /Ot /Oy /GT)
+    add_compile_options(/Ox /Ob2 /Ot /Oy)
+    # Avoid spam in clang-cl as it doesn't support /GT
+    if(CMAKE_C_COMPILER_ID STREQUAL "MSVC")
+        add_compile_options(/GT)
+    endif()
 elseif(OPTIMIZE STREQUAL "1")
     add_compile_options(/O1)
 elseif(OPTIMIZE STREQUAL "2")