diff --git a/wsjson/wsjson.go b/wsjson/wsjson.go
index 4d315d1f05fe8d2eda2ef89ce2481a38d4a54a11..9dd61bd012523f4938b9dd0e6a5086113b1bdd3e 100644
--- a/wsjson/wsjson.go
+++ b/wsjson/wsjson.go
@@ -29,6 +29,7 @@ func read(ctx context.Context, c *websocket.Conn, v interface{}) error {
 	}
 
 	if typ != websocket.MessageText {
+		c.Close(websocket.StatusUnsupportedData, "can only accept text messages")
 		return xerrors.Errorf("unexpected frame type for json (expected %v): %v", websocket.MessageText, typ)
 	}
 
diff --git a/wspb/wspb.go b/wspb/wspb.go
index 953128e7f251055b72dffd7b3cf602fc6bf2f011..90a0d0462c9689779ef633e3f0b53e1e810306ae 100644
--- a/wspb/wspb.go
+++ b/wspb/wspb.go
@@ -30,6 +30,7 @@ func read(ctx context.Context, c *websocket.Conn, v proto.Message) error {
 	}
 
 	if typ != websocket.MessageBinary {
+		c.Close(websocket.StatusUnsupportedData, "can only accept binary messages")
 		return xerrors.Errorf("unexpected frame type for protobuf (expected %v): %v", websocket.MessageBinary, typ)
 	}