diff --git a/src/highlight.c b/src/highlight.c
index 9476a7d..9c9e445 100644
--- a/src/highlight.c
+++ b/src/highlight.c
@@ -694,7 +694,7 @@
     /*
      * ":highlight {group-name}": list highlighting for one group.
      */
-    if (!doclear && !dolink && ends_excmd(*linep))
+    if (!doclear && !dolink && ends_excmd2(line, linep))
     {
 	id = syn_namen2id(line, (int)(name_end - line));
 	if (id == 0)
@@ -720,14 +720,14 @@
 	to_start = skipwhite(from_end);
 	to_end	 = skiptowhite(to_start);
 
-	if (ends_excmd(*from_start) || ends_excmd(*to_start))
+	if (ends_excmd2(line, from_start) || ends_excmd2(line, to_start))
 	{
 	    semsg(_("E412: Not enough arguments: \":highlight link %s\""),
 								  from_start);
 	    return;
 	}
 
-	if (!ends_excmd(*skipwhite(to_end)))
+	if (!ends_excmd2(line, skipwhite(to_end)))
 	{
 	    semsg(_("E413: Too many arguments: \":highlight link %s\""), from_start);
 	    return;
@@ -781,8 +781,7 @@
 	/*
 	 * ":highlight clear [group]" command.
 	 */
-	line = linep;
-	if (ends_excmd(*line))
+	if (ends_excmd2(line, linep))
 	{
 #ifdef FEAT_GUI
 	    // First, we do not destroy the old values, but allocate the new
@@ -826,7 +825,7 @@
 	    // It is now Ok to clear out the old data.
 #endif
 #ifdef FEAT_EVAL
-	    do_unlet((char_u *)"colors_name", TRUE);
+	    do_unlet((char_u *)"g:colors_name", TRUE);
 #endif
 	    restore_cterm_colors();
 
@@ -845,6 +844,7 @@
 	    redraw_later_clear();
 	    return;
 	}
+	line = linep;
 	name_end = skiptowhite(line);
 	linep = skipwhite(name_end);
     }
@@ -888,7 +888,7 @@
     }
 
     if (!doclear)
-      while (!ends_excmd(*linep))
+      while (!ends_excmd2(line, linep))
       {
 	key_start = linep;
 	if (*linep == '=')
@@ -4946,10 +4946,11 @@
     if (!eap->skip)
 	match_delete(curwin, id, FALSE);
 
-    if (ends_excmd(*eap->arg))
+    if (ends_excmd2(eap->cmd, eap->arg))
 	end = eap->arg;
     else if ((STRNICMP(eap->arg, "none", 4) == 0
-		&& (VIM_ISWHITE(eap->arg[4]) || ends_excmd(eap->arg[4]))))
+		&& (VIM_ISWHITE(eap->arg[4])
+				      || ends_excmd2(eap->arg, eap->arg + 4))))
 	end = eap->arg + 4;
     else
     {
@@ -4967,7 +4968,7 @@
 	end = skip_regexp(p + 1, *p, TRUE);
 	if (!eap->skip)
 	{
-	    if (*end != NUL && !ends_excmd(*skipwhite(end + 1)))
+	    if (*end != NUL && !ends_excmd2(end, skipwhite(end + 1)))
 	    {
 		vim_free(g);
 		eap->errmsg = e_trailing;
diff --git a/src/menu.c b/src/menu.c
index 38b4fd8..b017925 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -2680,7 +2680,7 @@
     /*
      * ":menutrans clear": clear all translations.
      */
-    if (STRNCMP(arg, "clear", 5) == 0 && ends_excmd(*skipwhite(arg + 5)))
+    if (STRNCMP(arg, "clear", 5) == 0 && ends_excmd2(arg, skipwhite(arg + 5)))
     {
 	tp = (menutrans_T *)menutrans_ga.ga_data;
 	for (i = 0; i < menutrans_ga.ga_len; ++i)
@@ -2703,7 +2703,9 @@
 	to = skipwhite(arg);
 	*arg = NUL;
 	arg = menu_skip_part(to);
-	if (arg == to)
+	if (arg == to || ends_excmd2(eap->arg, from)
+		      || ends_excmd2(eap->arg, to)
+		      || !ends_excmd2(eap->arg, skipwhite(arg)))
 	    emsg(_(e_invarg));
 	else
 	{
diff --git a/src/syntax.c b/src/syntax.c
index da5dfa1..cda1f95 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -3632,7 +3632,7 @@
     if (curwin->w_s->b_syn_topgrp != 0)
 	return;
 
-    if (ends_excmd(*arg))
+    if (ends_excmd2(eap->cmd, arg))
     {
 	/*
 	 * No argument: Clear all syntax items.
@@ -3652,7 +3652,7 @@
 	/*
 	 * Clear the group IDs that are in the argument.
 	 */
-	while (!ends_excmd(*arg))
+	while (!ends_excmd2(eap->cmd, arg))
 	{
 	    arg_end = skiptowhite(arg);
 	    if (*arg == '@')
@@ -3843,7 +3843,7 @@
     }
     else
 	msg_puts_title(_("\n--- Syntax items ---"));
-    if (ends_excmd(*arg))
+    if (ends_excmd2(eap->cmd, arg))
     {
 	/*
 	 * No argument: List all group IDs and all syntax clusters.
@@ -3858,7 +3858,7 @@
 	/*
 	 * List the group IDs and syntax clusters that are in the argument.
 	 */
-	while (!ends_excmd(*arg) && !got_int)
+	while (!ends_excmd2(eap->cmd, arg) && !got_int)
 	{
 	    arg_end = skiptowhite(arg);
 	    if (*arg == '@')
@@ -4463,11 +4463,12 @@
  */
     static char_u *
 get_syn_options(
-    char_u	    *arg,		// next argument to be checked
+    char_u	    *start,		// next argument to be checked
     syn_opt_arg_T   *opt,		// various things
     int		    *conceal_char UNUSED,
     int		    skip)		// TRUE if skipping over command
 {
+    char_u	*arg = start;
     char_u	*gname_start, *gname;
     int		syn_id;
     int		len;
@@ -4528,7 +4529,7 @@
 	    if (p[i] == NUL && (VIM_ISWHITE(arg[len])
 				    || (flagtab[fidx].argtype > 0
 					 ? arg[len] == '='
-					 : ends_excmd(arg[len]))))
+					 : ends_excmd2(start, arg + len))))
 	    {
 		if (opt->keyword
 			&& (flagtab[fidx].flags == HL_DISPLAY
@@ -4790,11 +4791,12 @@
 	     */
 	    cnt = 0;
 	    p = keyword_copy;
-	    for ( ; rest != NULL && !ends_excmd(*rest); rest = skipwhite(rest))
+	    for ( ; rest != NULL && !ends_excmd2(eap->arg, rest);
+							rest = skipwhite(rest))
 	    {
 		rest = get_syn_options(rest, &syn_opt_arg, &conceal_char,
 								    eap->skip);
-		if (rest == NULL || ends_excmd(*rest))
+		if (rest == NULL || ends_excmd2(eap->arg, rest))
 		    break;
 		// Copy the keyword, removing backslashes, and add a NUL.
 		while (*rest != NUL && !VIM_ISWHITE(*rest))
@@ -4892,6 +4894,7 @@
     syn_opt_arg_T syn_opt_arg;
     int		sync_idx = 0;
     int		conceal_char = NUL;
+    int		orig_called_emsg = called_emsg;
 
     // Isolate the group name, check for validity
     rest = get_group_name(arg, &group_name_end);
@@ -4922,7 +4925,7 @@
 	 * Check for trailing command and illegal trailing arguments.
 	 */
 	eap->nextcmd = check_nextcmd(rest);
-	if (!ends_excmd(*rest) || eap->skip)
+	if (!ends_excmd2(eap->cmd, rest) || eap->skip)
 	    rest = NULL;
 	else if (ga_grow(&curwin->w_s->b_syn_patterns, 1) != FAIL
 		&& (syn_id = syn_check_group(arg,
@@ -4974,7 +4977,7 @@
     vim_free(syn_opt_arg.cont_in_list);
     vim_free(syn_opt_arg.next_list);
 
-    if (rest == NULL)
+    if (rest == NULL && called_emsg == orig_called_emsg)
 	semsg(_(e_invarg2), arg);
 }
 
@@ -5037,11 +5040,11 @@
     /*
      * get the options, patterns and matchgroup.
      */
-    while (rest != NULL && !ends_excmd(*rest))
+    while (rest != NULL && !ends_excmd2(eap->cmd, rest))
     {
 	// Check for option arguments
 	rest = get_syn_options(rest, &syn_opt_arg, &conceal_char, eap->skip);
-	if (rest == NULL || ends_excmd(*rest))
+	if (rest == NULL || ends_excmd2(eap->cmd, rest))
 	    break;
 
 	// must be a pattern or matchgroup then
@@ -5570,7 +5573,7 @@
 
     if (!got_clstr)
 	emsg(_("E400: No cluster specified"));
-    if (rest == NULL || !ends_excmd(*rest))
+    if (rest == NULL || !ends_excmd2(eap->cmd, rest))
 	semsg(_(e_invarg2), arg);
 }
 
@@ -5680,7 +5683,7 @@
 	}
     } while (idx >= 0);
 
-    if (!ends_excmd(*end) && !VIM_ISWHITE(*end))
+    if (!ends_excmd2(arg, end) && !VIM_ISWHITE(*end))
     {
 	semsg(_("E402: Garbage after pattern: %s"), arg);
 	return NULL;
@@ -5703,13 +5706,13 @@
     long	n;
     char_u	*cpo_save;
 
-    if (ends_excmd(*arg_start))
+    if (ends_excmd2(eap->cmd, arg_start))
     {
 	syn_cmd_list(eap, TRUE);
 	return;
     }
 
-    while (!ends_excmd(*arg_start))
+    while (!ends_excmd2(eap->cmd, arg_start))
     {
 	arg_end = skiptowhite(arg_start);
 	next_arg = skipwhite(arg_end);
@@ -5719,7 +5722,7 @@
 	{
 	    if (!eap->skip)
 		curwin->w_s->b_syn_sync_flags |= SF_CCOMMENT;
-	    if (!ends_excmd(*next_arg))
+	    if (!ends_excmd2(eap->cmd, next_arg))
 	    {
 		arg_end = skiptowhite(next_arg);
 		if (!eap->skip)
@@ -5888,7 +5891,7 @@
 	    break;
 	}
 	p = skipwhite(p + 1);
-	if (ends_excmd(*p))
+	if (ends_excmd2(*arg, p))
 	{
 	    semsg(_("E406: Empty argument: %s"), *arg);
 	    break;
@@ -5898,7 +5901,7 @@
 	 * parse the arguments after "contains"
 	 */
 	count = 0;
-	while (!ends_excmd(*p))
+	while (!ends_excmd2(*arg, p))
 	{
 	    for (end = p; *end && !VIM_ISWHITE(*end) && *end != ','; ++end)
 		;
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index a541d88..219a86f 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -1210,6 +1210,176 @@
       'vim9script',
       'hi# comment',
       ], 'E416:')
+  CheckScriptSuccess([
+      'vim9script',
+      'hi Search # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'hi Search# comment',
+      ], 'E416:')
+  CheckScriptSuccess([
+      'vim9script',
+      'hi link This Search # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'hi link This That# comment',
+      ], 'E413:')
+  CheckScriptSuccess([
+      'vim9script',
+      'hi clear This # comment',
+      'hi clear # comment',
+      ])
+  " not tested, because it doesn't give an error but a warning:
+  " hi clear This# comment',
+  CheckScriptFailure([
+      'vim9script',
+      'hi clear# comment',
+      ], 'E416:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'hi Group term=bold',
+      'match Group /todo/ # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'hi Group term=bold',
+      'match Group /todo/# comment',
+      ], 'E488:')
+  CheckScriptSuccess([
+      'vim9script',
+      'match # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'match# comment',
+      ], 'E475:')
+  CheckScriptSuccess([
+      'vim9script',
+      'match none # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'match none# comment',
+      ], 'E475:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'menutrans clear # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'menutrans clear# comment text',
+      ], 'E474:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax clear # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax clear# comment text',
+      ], 'E28:')
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax keyword Word some',
+      'syntax clear Word # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax keyword Word some',
+      'syntax clear Word# comment text',
+      ], 'E28:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax list # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax list# comment text',
+      ], 'E28:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax match Word /pat/ oneline # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax match Word /pat/ oneline# comment',
+      ], 'E475:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax keyword Word word # comm[ent',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax keyword Word word# comm[ent',
+      ], 'E789:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax match Word /pat/ # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax match Word /pat/# comment',
+      ], 'E402:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax match Word /pat/ contains=Something # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax match Word /pat/ contains=Something# comment',
+      ], 'E475:')
+  CheckScriptFailure([
+      'vim9script',
+      'syntax match Word /pat/ contains= # comment',
+      ], 'E406:')
+  CheckScriptFailure([
+      'vim9script',
+      'syntax match Word /pat/ contains=# comment',
+      ], 'E475:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax region Word start=/pat/ end=/pat/ # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax region Word start=/pat/ end=/pat/# comment',
+      ], 'E475:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax sync # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax sync# comment',
+      ], 'E404:')
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax sync ccomment # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax sync ccomment# comment',
+      ], 'E404:')
+
+  CheckScriptSuccess([
+      'vim9script',
+      'syntax cluster Some contains=Word # comment',
+      ])
+  CheckScriptFailure([
+      'vim9script',
+      'syntax cluster Some contains=Word# comment',
+      ], 'E475:')
 enddef
 
 def Test_vim9_comment_gui()
diff --git a/src/version.c b/src/version.c
index de9413b..9b00c49 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    613,
+/**/
     612,
 /**/
     611,