diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6233508e3d..e6d3ed2d88 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -49,7 +49,7 @@ if ( MSVC )
 
     # Set always to static runtime
     set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT")
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /MTd")
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /MTd /DDEBUG")
     if (CMAKE_BUILD_TYPE STREQUAL "Debug")
         set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreadedDebug")
         set(CMAKE_MSVC_RUNTIME_LIBRARY_FLAG "MTd")
diff --git a/src/util.h b/src/util.h
index 0b41c7cd89..3988199368 100644
--- a/src/util.h
+++ b/src/util.h
@@ -41,6 +41,9 @@
 
 #include <cassert>
 
+#ifdef ASSERT
+#undef ASSERT
+#endif
 #define ASSERT(x) assert(x)
 #define DEBUG_MSG(...) fprintf(stderr, __VA_ARGS__)
 #define DEBUG_fputs fputs