diff --git a/configure.ac b/configure.ac
index d8f8148..1c5ef4f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -95,6 +95,9 @@ mingw* | cygwin*)
 	AM_CONDITIONAL([LINUX], false)
 	AM_CONDITIONAL([WIN32], true)
 	AM_CONDITIONAL([MACOSX], false)
+	# Set WINVER to 0x0501 (corresponds to Windows XP), needed for some
+	# defineѕ such as WC_NO_BEST_FIT_CHARS.
+	CFLAGS="$CFLAGS -DWINVER=0x0501"
 	SP_LIBS="-lsetupapi -luuid"
 	;;
 *)