diff --git a/highlighters/main/main-highlighter.zsh b/highlighters/main/main-highlighter.zsh
index 66a3d2a..e4a17e0 100644
--- a/highlighters/main/main-highlighter.zsh
+++ b/highlighters/main/main-highlighter.zsh
@@ -1689,8 +1689,13 @@ _zsh_highlight_main_highlighter_expand_path()
 # -------------------------------------------------------------------------------------------------
 
 _zsh_highlight_main__precmd_hook() {
+  # Unset the WARN_NESTED_VAR option, taking care not to error if the option
+  # doesn't exist (zsh older than zsh-5.3.1-test-2).
   setopt localoptions
-  unsetopt warnnestedvar
+  if [[ -o warnnestedvar ]] 2>/dev/null; then
+    unsetopt warnnestedvar
+  fi
+
   _zsh_highlight_main__command_type_cache=()
 }