diff --git a/src/common/sigslot.h b/src/common/sigslot.h
index 20002ec..c2247f5 100644
--- a/src/common/sigslot.h
+++ b/src/common/sigslot.h
@@ -85,6 +85,7 @@
 #	define _SIGSLOT_SINGLE_THREADED
 #elif defined(WIN32)
 #	define _SIGSLOT_HAS_WIN32_THREADS
+#	define WIN32_LEAN_AND_MEAN
 #	include <windows.h>
 #elif defined(__GNUG__) || defined(SIGSLOT_USE_POSIX_THREADS)
 #	define _SIGSLOT_HAS_POSIX_THREADS