diff --git a/highlighters/main/main-highlighter.zsh b/highlighters/main/main-highlighter.zsh
index c2f68d7..2586206 100644
--- a/highlighters/main/main-highlighter.zsh
+++ b/highlighters/main/main-highlighter.zsh
@@ -553,7 +553,17 @@ _zsh_highlight_main_highlighter_highlight_list()
          [[ ${parameter_name} =~ ^([A-Za-z_][A-Za-z0-9_]*|[0-9]+)$ ]] &&
          (( ${+parameters[(e)${MATCH}]} )) && [[ ${parameters[(e)$MATCH]} != *special* ]]
          then
-        arg=${(P)MATCH}
+        # Set $arg.
+        case ${(tP)MATCH} in
+          (*array*|*assoc*)
+            local -a words; words=( ${(P)MATCH} )
+            arg=${words[1]}
+            ;;
+          (*)
+            # scalar, presumably
+            arg=${(P)MATCH}
+            ;;
+        esac
         _zsh_highlight_main__type "$arg"
         res=$REPLY
       fi
diff --git a/highlighters/main/test-data/commmand-parameter.zsh b/highlighters/main/test-data/commmand-parameter.zsh
index afa9bc5..48d20ba 100644
--- a/highlighters/main/test-data/commmand-parameter.zsh
+++ b/highlighters/main/test-data/commmand-parameter.zsh
@@ -29,9 +29,10 @@
 
 local x=/usr/bin/env
 local y=sudo
+local -a z; z=(zsh -f)
 sudo(){}
 
-BUFFER='$x "argument"; $y'
+BUFFER='$x "argument"; $y; $z'
 
 expected_region_highlight=(
   "1 2 command" # $x
@@ -39,4 +40,6 @@ expected_region_highlight=(
   "4 13 double-quoted-argument" # "argument"
   "14 14 commandseparator" # ;
   "16 17 precommand" # $y (sudo)
+  "18 18 unknown-token" # ;
+  "20 21 command" # $z - 'zsh' being the command
 )