diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5516dbdb..4b117f00 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -175,6 +175,10 @@ if (NOT NO_DEBUG)
     set(CMAKE_VALA_FLAGS "${CMAKE_VALA_FLAGS} -g")
 endif (NOT NO_DEBUG)
 
+if (WIN32)
+    set(CMAKE_VALA_FLAGS "${CMAKE_VALA_FLAGS} --define=_WIN32")
+endif(WIN32)
+
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 
diff --git a/libdino/src/service/util.vala b/libdino/src/service/util.vala
index 9fe3029c..bb7198d3 100644
--- a/libdino/src/service/util.vala
+++ b/libdino/src/service/util.vala
@@ -29,7 +29,7 @@ public class Util {
     
     public static string get_content_type(FileInfo fileInfo)
     {
-//#if WIN32
+#if _WIN32
         string fileName = fileInfo.get_name();
         int fileNameLength = fileName.length;
         int extIndex = fileName.index_of(".");
@@ -42,8 +42,7 @@ public class Util {
                 return mime_type;
             }
         }
-//#endif
-
+#endif
         return fileInfo.get_content_type();
     }
 }