diff --git a/configure.ac b/configure.ac
index 2ce790cb55a600d81cc10deaa6db3e6365b5a8de..5a202d0a32aa1817c2154ec984a85dd12b848a89 100644
--- a/configure.ac
+++ b/configure.ac
@@ -74,7 +74,7 @@ case "${host_os}" in
     AC_DEFINE([_BSD_SOURCE], [1], [ISO C, POSIX, and 4.3BSD things.])
     AC_DEFINE([_SVID_SOURCE], [1], [ISO C, POSIX, and SVID things.])
 
-    AC_DEFINE([WIN32_LEAN_AND_MEAN],, [Define to limit the scope of <windows.h>.])
+    AC_DEFINE([WIN32_LEAN_AND_MEAN],[1], [Define to limit the scope of <windows.h>.])
 
     CPPFLAGS+="-D_WIN32_WINNT=0x0601 -DWINVER=0x0601 -D__USE_MINGW_ANSI_STDIO=1"
     LDFLAGS+="-no-undefined -avoid-version -Wl,--nxcompat -Wl,--dynamicbase"
diff --git a/src/winsyslog.h b/src/winsyslog.h
index 514de7dfa51e10a0fcb8ec790e22827dd5edc75b..3696ff335e5c0638fe63a0a5415e21feec663491 100644
--- a/src/winsyslog.h
+++ b/src/winsyslog.h
@@ -13,7 +13,9 @@
 
 #ifndef WINSYSLOG_H
 #define WINSYSLOG_H
-#define WIN32_LEAN_AND_MEAN
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN 1
+#endif
 #include <windows.h>
 
 #define WINLOG_PRIMASK  0x07