diff --git a/command/backtrace.sh b/command/backtrace.sh
index b735353..7aecade 100644
--- a/command/backtrace.sh
+++ b/command/backtrace.sh
@@ -130,7 +130,7 @@ function _Dbg_do_backtrace {
 	((count--)) ;
 	adjusted_pos=$(_Dbg_frame_adjusted_pos 0)
 	filename="$(_Dbg_resolve_expand_filename "${BASH_SOURCE[$adjusted_pos]}")"
-	filename=$(_Dbg_adjust_filename "$filename")
+	filename="$(_Dbg_adjust_filename "$filename")"
 	_Dbg_frame_print $(_Dbg_frame_prefix 0) '0' '' "$filename" "$_Dbg_frame_last_lineno" ''
     fi