diff --git a/lib/nghttp2_session.c b/lib/nghttp2_session.c
index d3fd37aa..2c927bb6 100644
--- a/lib/nghttp2_session.c
+++ b/lib/nghttp2_session.c
@@ -1706,6 +1706,9 @@ static int session_predicate_altsvc_send(nghttp2_session *session,
   if (stream == NULL) {
     return NGHTTP2_ERR_STREAM_CLOSED;
   }
+  if (stream->state == NGHTTP2_STREAM_CLOSING) {
+    return NGHTTP2_ERR_STREAM_CLOSING;
+  }
 
   return 0;
 }