diff --git a/src/vim9compile.c b/src/vim9compile.c
index 458b4a1..238ce5d 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -1546,7 +1546,7 @@
     isn->isn_arg.funcref.fr_func = ufunc->uf_dfunc_idx;
     cctx->ctx_has_closure = 1;
 
-    // if the referenced function is a closure, it may use items further up in
+    // If the referenced function is a closure, it may use items further up in
     // the nested context, including this one.
     if (ufunc->uf_flags & FC_CLOSURE)
 	cctx->ctx_ufunc->uf_flags |= FC_CLOSURE;
@@ -2401,6 +2401,8 @@
 	if (line != NULL)
 	{
 	    p = skipwhite(line);
+	    if (vim9_bad_comment(p))
+		return NULL;
 	    if (*p != NUL && !vim9_comment_start(p))
 		return p;
 	}
@@ -2465,6 +2467,8 @@
 may_get_next_line(char_u *whitep, char_u **arg, cctx_T *cctx)
 {
     *arg = skipwhite(whitep);
+    if (vim9_bad_comment(*arg))
+	return FAIL;
     if (**arg == NUL || (VIM_ISWHITE(*whitep) && vim9_comment_start(*arg)))
     {
 	char_u *next = next_line_from_context(cctx, TRUE);
@@ -4277,10 +4281,13 @@
 
 	if (!eval_isnamec1(**arg))
 	{
-	    if (ends_excmd(*skipwhite(*arg)))
-		semsg(_(e_empty_expression_str), *arg);
-	    else
-		semsg(_(e_name_expected_str), *arg);
+	    if (!vim9_bad_comment(*arg))
+	    {
+		if (ends_excmd(*skipwhite(*arg)))
+		    semsg(_(e_empty_expression_str), *arg);
+		else
+		    semsg(_(e_name_expected_str), *arg);
+	    }
 	    return FAIL;
 	}
 
@@ -8297,6 +8304,8 @@
 	    semsg(_(e_trailing_arg), line);
 	    goto erret;
 	}
+	else if (line != NULL && vim9_bad_comment(skipwhite(line)))
+	    goto erret;
 	else
 	{
 	    line = next_line_from_context(&cctx, FALSE);