diff --git a/BasiliskII/src/Unix/configure.ac b/BasiliskII/src/Unix/configure.ac
index ab800984..53e247db 100644
--- a/BasiliskII/src/Unix/configure.ac
+++ b/BasiliskII/src/Unix/configure.ac
@@ -250,7 +250,7 @@ else
 fi
 
 dnl We need X11, if not using SDL.
-if [[ "x$WANT_SDL" = "xno" ]]; then
+if [[ "x$WANT_SDL_VIDEO" = "xno" ]]; then
   AC_PATH_XTRA
   if [[ "x$no_x" = "xyes" ]]; then
     AC_MSG_ERROR([You need X11 to run Basilisk II.])