diff --git a/reactos/dll/3rdparty/libtiff/CMakeLists.txt b/reactos/dll/3rdparty/libtiff/CMakeLists.txt
index 27ec6ad2bb5..6ea7bb06e29 100644
--- a/reactos/dll/3rdparty/libtiff/CMakeLists.txt
+++ b/reactos/dll/3rdparty/libtiff/CMakeLists.txt
@@ -61,5 +61,7 @@ add_cd_file(TARGET libtiff DESTINATION reactos/system32 FOR all)
 
 if(NOT MSVC)
     allow_warnings(libtiff)
-    add_target_compile_flags(libtiff "-Wno-unused-but-set-variable")
+    if(NOT CMAKE_C_COMPILER_ID STREQUAL "Clang")
+        add_target_compile_flags(libtiff "-Wno-unused-but-set-variable")
+    endif()
 endif()
diff --git a/reactos/dll/3rdparty/libxslt/CMakeLists.txt b/reactos/dll/3rdparty/libxslt/CMakeLists.txt
index 988a7ca3c29..648ca8d4a62 100644
--- a/reactos/dll/3rdparty/libxslt/CMakeLists.txt
+++ b/reactos/dll/3rdparty/libxslt/CMakeLists.txt
@@ -48,5 +48,8 @@ add_pch(libxslt precomp.h SOURCE)
 add_cd_file(TARGET libxslt DESTINATION reactos/system32 FOR all)
 
 if(NOT MSVC)
-    add_target_compile_flags(libxslt "-Wno-pointer-sign -Wno-unused-but-set-variable -Wno-unused-function")
+    add_target_compile_flags(libxslt "-Wno-pointer-sign -Wno-unused-function")
+    if(NOT CMAKE_C_COMPILER_ID STREQUAL "Clang")
+        add_target_compile_flags(libxslt "-Wno-unused-but-set-variable")
+    endif()
 endif()
diff --git a/reactos/dll/opengl/glu32/CMakeLists.txt b/reactos/dll/opengl/glu32/CMakeLists.txt
index 4c15d12325e..34471408c8f 100644
--- a/reactos/dll/opengl/glu32/CMakeLists.txt
+++ b/reactos/dll/opengl/glu32/CMakeLists.txt
@@ -113,11 +113,13 @@ add_library(glu32 SHARED ${SOURCE} glu32.rc)
 set_module_type(glu32 win32dll)
 
 if(NOT MSVC)
-    add_target_compile_flags(glu32 "-Wno-write-strings -Wno-unused-but-set-variable")
+    add_target_compile_flags(glu32 "-Wno-write-strings")
     if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
         target_link_libraries(glu32 mingwex)
         #FIXME: longjmp exists in both our msvcrt and mingwex
         add_target_link_flags(glu32 "-Wl,--allow-multiple-definition")
+    else()
+        add_target_compile_flags(glu32 "-Wno-unused-but-set-variable")
     endif()
 endif()
 
diff --git a/reactos/dll/win32/browseui/CMakeLists.txt b/reactos/dll/win32/browseui/CMakeLists.txt
index e5f39bc01d3..2c1e04c067c 100644
--- a/reactos/dll/win32/browseui/CMakeLists.txt
+++ b/reactos/dll/win32/browseui/CMakeLists.txt
@@ -60,7 +60,9 @@ add_pch(browseui precomp.h SOURCE)
 add_cd_file(TARGET browseui DESTINATION reactos/system32 FOR all)
 
 if(NOT MSVC)
-    add_target_compile_flags(browseui "-Wno-unused-but-set-variable")
+    if(NOT CMAKE_C_COMPILER_ID STREQUAL "Clang")
+        add_target_compile_flags(browseui "-Wno-unused-but-set-variable")
+    endif()
 
     # Binutils linker bug
     if(LTCG)
diff --git a/reactos/dll/win32/winmm/CMakeLists.txt b/reactos/dll/win32/winmm/CMakeLists.txt
index 6123003f1ca..0c59c51db63 100644
--- a/reactos/dll/win32/winmm/CMakeLists.txt
+++ b/reactos/dll/win32/winmm/CMakeLists.txt
@@ -29,6 +29,6 @@ add_pch(winmm winemm.h SOURCE)
 add_subdirectory(midimap)
 add_cd_file(TARGET winmm DESTINATION reactos/system32 FOR all)
 
-if(NOT MSVC)
+if((NOT MSVC) AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
     add_target_compile_flags(winmm "-Wno-unused-but-set-variable")
 endif()
diff --git a/reactos/drivers/bluetooth/fbtusb/CMakeLists.txt b/reactos/drivers/bluetooth/fbtusb/CMakeLists.txt
index 5b8288f5c12..f3f9d190a53 100644
--- a/reactos/drivers/bluetooth/fbtusb/CMakeLists.txt
+++ b/reactos/drivers/bluetooth/fbtusb/CMakeLists.txt
@@ -12,8 +12,8 @@ list(APPEND SOURCE
 
 add_library(fbtusb SHARED ${SOURCE} fbtusb.rc)
 
-if(NOT MSVC)
-    set_source_files_properties(${SOURCE} PROPERTIES COMPILE_FLAGS "-Wno-unused-but-set-variable")
+if((NOT MSVC) AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
+    add_target_compile_flags(fbtusb "-Wno-unused-but-set-variable")
 endif()
 
 set_module_type(fbtusb kernelmodedriver)
diff --git a/reactos/drivers/filesystems/ext2/CMakeLists.txt b/reactos/drivers/filesystems/ext2/CMakeLists.txt
index afb66a6a2ed..8e1f9529efe 100644
--- a/reactos/drivers/filesystems/ext2/CMakeLists.txt
+++ b/reactos/drivers/filesystems/ext2/CMakeLists.txt
@@ -24,8 +24,8 @@ list(APPEND SOURCE
 
 add_library(ext2fs SHARED ${SOURCE})
 
-if(NOT MSVC)
-    add_compile_flags("-Wno-unused-but-set-variable")
+if((NOT MSVC) AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
+    add_target_compile_flags(ext2fs "-Wno-unused-but-set-variable")
 endif()
 
 target_link_libraries(ext2fs ${PSEH_LIB})
diff --git a/reactos/drivers/storage/ide/uniata/CMakeLists.txt b/reactos/drivers/storage/ide/uniata/CMakeLists.txt
index 2236e470c05..922d18e7a11 100644
--- a/reactos/drivers/storage/ide/uniata/CMakeLists.txt
+++ b/reactos/drivers/storage/ide/uniata/CMakeLists.txt
@@ -22,7 +22,10 @@ add_library(uniata SHARED ${SOURCE} idedma.rc)
 
 
 if(NOT MSVC)
-    set_source_files_properties(${SOURCE} PROPERTIES COMPILE_FLAGS "-Wno-unused-but-set-variable -Wno-narrowing")
+    add_target_compile_flags(uniata "-Wno-narrowing")
+    if(NOT CMAKE_C_COMPILER_ID STREQUAL "Clang")
+        add_target_compile_flags(uniata "-Wno-unused-but-set-variable")
+    endif()
 endif()
 
 add_pch(uniata stdafx.h SOURCE)
diff --git a/reactos/lib/3rdparty/adns/CMakeLists.txt b/reactos/lib/3rdparty/adns/CMakeLists.txt
index e85e7070537..b8187d8fd17 100644
--- a/reactos/lib/3rdparty/adns/CMakeLists.txt
+++ b/reactos/lib/3rdparty/adns/CMakeLists.txt
@@ -25,6 +25,6 @@ add_library(adns ${SOURCE})
 add_dependencies(adns psdk)
 add_pch(adns src/internal.h SOURCE)
 
-if(NOT MSVC)
+if((NOT MSVC) AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
     add_target_compile_flags(adns "-Wno-unused-but-set-variable")
 endif()
diff --git a/reactos/lib/3rdparty/cardlib/CMakeLists.txt b/reactos/lib/3rdparty/cardlib/CMakeLists.txt
index 8369f57d970..d624197436a 100644
--- a/reactos/lib/3rdparty/cardlib/CMakeLists.txt
+++ b/reactos/lib/3rdparty/cardlib/CMakeLists.txt
@@ -19,6 +19,6 @@ add_library(cardlib ${SOURCE})
 add_dependencies(cardlib psdk)
 add_pch(cardlib cardlib.h SOURCE)
 
-if(NOT MSVC AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
+if((NOT MSVC) AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
     add_target_compile_flags(cardlib "-Wno-unused-but-set-variable")
 endif()
diff --git a/reactos/lib/3rdparty/fullfat/CMakeLists.txt b/reactos/lib/3rdparty/fullfat/CMakeLists.txt
index 6163ff51e23..ec426f1f688 100644
--- a/reactos/lib/3rdparty/fullfat/CMakeLists.txt
+++ b/reactos/lib/3rdparty/fullfat/CMakeLists.txt
@@ -19,6 +19,6 @@ list(APPEND SOURCE
 add_library(fullfat ${SOURCE})
 add_dependencies(fullfat bugcodes)
 
-if(NOT MSVC)
+if((NOT MSVC) AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
     add_target_compile_flags(fullfat "-Wno-unused-but-set-variable")
 endif()
diff --git a/reactos/lib/3rdparty/libmpg123/CMakeLists.txt b/reactos/lib/3rdparty/libmpg123/CMakeLists.txt
index 3731927f62e..954682f000a 100644
--- a/reactos/lib/3rdparty/libmpg123/CMakeLists.txt
+++ b/reactos/lib/3rdparty/libmpg123/CMakeLists.txt
@@ -45,6 +45,6 @@ add_library(libmpg123 ${SOURCE})
 add_dependencies(libmpg123 psdk)
 add_pch(libmpg123 precomp.h SOURCE)
 
-if(NOT MSVC)
+if((NOT MSVC) AND (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang"))
     add_target_compile_flags(libmpg123 "-Wno-unused-but-set-variable")
 endif()