diff --git a/CMakeLists.txt b/CMakeLists.txt
index e035a5c538..f765036cdd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -80,6 +80,17 @@ IF(WIN32)
   ENDIF()
 ENDIF()
 
+# set warning level 4
+IF(MSVC)
+  if(CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
+    string(REGEX REPLACE "/W[0-4]" "/W4" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+  else()
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+  endif()
+elseif(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
+endif()
+
 SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DNo_Exception")
 SET(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -DNo_Exception")