Index: configure.ac
===================================================================
--- configure.ac	(revision 299311)
+++ configure.ac	(working copy)
@@ -432,7 +432,7 @@
 AST_EXT_LIB_SETUP([RESAMPLE], [LIBRESAMPLE], [resample])
 AST_EXT_LIB_SETUP([SDL], [Sdl], [sdl])
 AST_EXT_LIB_SETUP([SDL_IMAGE], [Sdl Image], [SDL_image])
-AST_OPTION_ONLY([sounds-cache], [SOUNDS_CACHE_DIR], [cached sound tarfiles], [${HOME}/.asterisk_sounds_cache])
+AST_OPTION_ONLY([sounds-cache], [SOUNDS_CACHE_DIR], [cached sound tarfiles], [])
 AST_EXT_LIB_SETUP([SPANDSP], [SPANDSP], [spandsp])
 AST_EXT_LIB_SETUP([SS7], [ISDN SS7], [ss7])
 AST_EXT_LIB_SETUP([SPEEX], [Speex], [speex])
Index: autoconf/ast_ext_lib.m4
===================================================================
--- autoconf/ast_ext_lib.m4	(revision 299311)
+++ autoconf/ast_ext_lib.m4	(working copy)
@@ -54,7 +54,7 @@
 		;;
 	esac
 	],
-	[m4_ifval($4, [$2="$4"])])
+	[m4_ifval($4, [$2="$4"], [:])])
 AC_SUBST($2)
 ])