diff --git a/CMakeLists.txt b/CMakeLists.txt
index c5d23d7ee8b..4aae844d008 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -182,10 +182,6 @@ if (MINGW)
     # the atomic primitives
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=i686")
   endif ()
-  # disable this optimisation because it breaks release builds (reason unknown)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-tree-slp-vectorize")
-  # Ignore some really annoying warnings which also happen in dependencies
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=cast-qual -Wno-unused-local-typedefs")
 endif ()
 
 include(GenerateExportHeader)