--- a/configure
+++ b/configure
@@ -790,10 +790,10 @@
 
 # additional options
 # Check whether --enable-xosd or --disable-xosd was given.
-if test "${enable_xosd+set}" = set; then
-  enableval="$enable_xosd"
+if test "x${enable_xosd}" = xno; then
   enable_xosd=no
 else
+  enableval="$enable_xosd"
   enable_xosd=yes
 fi