diff --git a/libaegisub/common/dispatch.cpp b/libaegisub/common/dispatch.cpp
index 434195836..7b1ed3ac6 100644
--- a/libaegisub/common/dispatch.cpp
+++ b/libaegisub/common/dispatch.cpp
@@ -14,6 +14,11 @@
 //
 // Aegisub Project http://www.aegisub.org/
 
+#ifdef _WIN32
+// For Boost::asio
+#include <sdkddkver.h>
+#endif
+
 #include "libaegisub/dispatch.h"
 
 #include "libaegisub/util.h"