diff --git a/fast-highlight b/fast-highlight
index 7a72683..b57f41e 100644
--- a/fast-highlight
+++ b/fast-highlight
@@ -611,9 +611,10 @@ typeset -ga ZLAST_COMMANDS
       (( next_word = (next_word & ~2) | 4 | 1 ))
      else
        _mybuf=${${(Q)__arg}#\"}
-       if [[ $_mybuf = (#b)(*)(*)\$([a-zA-Z_][a-zA-Z0-9_]#|[0-9]##)(*) || \
+       if (( ${+parameters} )) && \
+          [[ $_mybuf = (#b)(*)(*)\$([a-zA-Z_][a-zA-Z0-9_]#|[0-9]##)(*) || \
              $_mybuf = (#b)(*)(*)\$\{([a-zA-Z_][a-zA-Z0-9_:-]#|[0-9]##)(*) ]] && \
-         [[ -v ${match[3]%%:-*} ]]
+         (( ${+parameters[${match[3]%%:-*}]} ))
        then
          -fast-highlight-main-type ${match[1]}${match[2]}${(P)match[3]%%:-*}${match[4]#\}}
        elif [[ $braces_stack = T* ]]; then # T - typedef, etc.
@@ -1342,7 +1343,7 @@ zle -N -- fast-highlight-check-path-handler -fast-highlight-check-path-handler
 
     [[ ${match[1]} = [0-9]* ]] && __style=${FAST_HIGHLIGHT_STYLES[${FAST_THEME_NAME}mathnum]} || {
       [[ ${match[1]} = [a-zA-Z_]* ]] && {
-        [[ -v ${match[1]} || ${FAST_ASSIGNS_SEEN[${match[1]}]} = 1 ]] && \
+        [[ ${+parameters[${match[1]}]} = 1 || ${FAST_ASSIGNS_SEEN[${match[1]}]} = 1 ]] && \
             __style=${FAST_HIGHLIGHT_STYLES[${FAST_THEME_NAME}mathvar]} || \
             __style=${FAST_HIGHLIGHT_STYLES[${FAST_THEME_NAME}matherr]}
       } || {