diff --git a/highlighters/main/main-highlighter.zsh b/highlighters/main/main-highlighter.zsh
index f820bd7..d4daeca 100755
--- a/highlighters/main/main-highlighter.zsh
+++ b/highlighters/main/main-highlighter.zsh
@@ -153,9 +153,9 @@ _zsh_highlight_main_highlighter_check_assign()
 # Check if the argument is a path.
 _zsh_highlight_main_highlighter_check_path()
 {
-  [[ -z ${(Q)~arg} ]] && return 1
-  [[ -e ${(Q)~arg} ]] && return 0
-  [[ ! -e ${(Q)~arg:h} ]] && return 1
+  [[ -z "${(Q)~arg}" ]] && return 1
+  [[ -e "${(Q)~arg}" ]] && return 0
+  [[ ! -e "${(Q)~arg:h}" ]] && return 1
   [[ ${BUFFER[1]} != "-" && ${#BUFFER} == $end_pos && -n $(print "${(Q)~arg}"*(N)) ]] && return 0
   return 1
 }