diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index b616740..001ccd7 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -4841,7 +4841,7 @@
     if (*arg == '+')	    /* +[command] */
     {
 	++arg;
-	if (vim_isspace(*arg))
+	if (vim_isspace(*arg) || *arg == NUL)
 	    command = dollar_command;
 	else
 	{