diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index b73eb95..134a488 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3871,7 +3871,6 @@
 	case CMD_cfdo:
 	case CMD_confirm:
 	case CMD_debug:
-	case CMD_filter:
 	case CMD_folddoclosed:
 	case CMD_folddoopen:
 	case CMD_hide:
@@ -3896,6 +3895,16 @@
 	case CMD_windo:
 	    return arg;
 
+	case CMD_filter:
+	    if (*arg != NUL)
+		arg = skip_vimgrep_pat(arg, NULL, NULL);
+	    if (arg == NULL || *arg == NUL)
+	    {
+		xp->xp_context = EXPAND_NOTHING;
+		return NULL;
+	    }
+	    return skipwhite(arg);
+
 #ifdef FEAT_CMDL_COMPL
 # ifdef FEAT_SEARCH_EXTRA
 	case CMD_match: