diff --git a/mkspecs/features/warnings.pri b/mkspecs/features/warnings.pri
index 86663b55b..ceaee60ef 100644
--- a/mkspecs/features/warnings.pri
+++ b/mkspecs/features/warnings.pri
@@ -2,7 +2,7 @@ msvc:DEFINES *= _SCL_SECURE_NO_WARNINGS
 
 # swift standard warnings
 msvc:QMAKE_CXXFLAGS_WARN_ON *= /wd4351 /wd4661
-clang_cl:QMAKE_CXXFLAGS_WARN_ON *= -Wall -Wextra -Wno-unknown-pragmas -Wno-undefined-inline -Wno-self-assign-overloaded
+clang_cl:QMAKE_CXXFLAGS_WARN_ON *= /W4 -Wno-unknown-pragmas -Wno-undefined-inline -Wno-self-assign-overloaded
 gcc:QMAKE_CXXFLAGS_WARN_ON *= -Woverloaded-virtual
 gcc:QMAKE_CXXFLAGS_USE_PRECOMPILE = -Winvalid-pch $$QMAKE_CXXFLAGS_USE_PRECOMPILE