diff --git a/src/vim9compile.c b/src/vim9compile.c
index e8a3a21..a53f05d 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -6903,7 +6903,8 @@
 	if (ea.cmdidx != CMD_SIZE
 			    && ea.cmdidx != CMD_write && ea.cmdidx != CMD_read)
 	{
-	    ea.argt = excmd_get_argt(ea.cmdidx);
+	    if (ea.cmdidx >= 0)
+		ea.argt = excmd_get_argt(ea.cmdidx);
 	    if ((ea.argt & EX_BANG) && *p == '!')
 	    {
 		ea.forceit = TRUE;