diff --git a/config.lib b/config.lib
--- a/config.lib
+++ b/config.lib
@@ -376,6 +376,7 @@ detect_params() {
 
 			--with-fluidsynth)            with_fluidsynth="2";;
 			--without-fluidsynth)         with_fluidsynth="0";;
+			--with-fluidsynth=*)          with_fluidsynth="$optarg";;
 
 			--with-freetype)              with_freetype="2";;
 			--without-freetype)           with_freetype="0";;