diff --git a/lib/core-net/private-lib-core-net.h b/lib/core-net/private-lib-core-net.h
index b75e023ea..1f566178b 100644
--- a/lib/core-net/private-lib-core-net.h
+++ b/lib/core-net/private-lib-core-net.h
@@ -1117,8 +1117,8 @@ lws_rxflow_cache(struct lws *wsi, unsigned char *buf, size_t n, size_t len);
 int
 lws_service_flag_pending(struct lws_context *context, int tsi);
 
-static LWS_INLINE int
-lws_has_buffered_out(struct lws *wsi) { return !!wsi->buflist_out; }
+int
+lws_has_buffered_out(struct lws *wsi);
 
 int LWS_WARN_UNUSED_RESULT
 lws_ws_client_rx_sm(struct lws *wsi, unsigned char c);
diff --git a/lib/core-net/wsi.c b/lib/core-net/wsi.c
index 84c6723e6..7a0ffeaed 100644
--- a/lib/core-net/wsi.c
+++ b/lib/core-net/wsi.c
@@ -622,6 +622,24 @@ lws_get_ssl(struct lws *wsi)
 }
 #endif
 
+int
+lws_has_buffered_out(struct lws *wsi)
+{
+	if (wsi->buflist_out)
+		return 1;
+
+#if defined(LWS_ROLE_H2)
+	{
+		struct lws *nwsi = lws_get_network_wsi(wsi);
+
+		if (nwsi->buflist_out)
+			return 1;
+	}
+#endif
+
+	return 0;
+}
+
 int
 lws_partial_buffered(struct lws *wsi)
 {