diff --git a/include/libwebsockets/lws-misc.h b/include/libwebsockets/lws-misc.h
index 2a33eba53..073108ad4 100644
--- a/include/libwebsockets/lws-misc.h
+++ b/include/libwebsockets/lws-misc.h
@@ -335,6 +335,15 @@ lws_get_library_version(void);
 LWS_VISIBLE LWS_EXTERN void *
 lws_wsi_user(struct lws *wsi);
 
+/**
+ * lws_wsi_tsi() - get the service thread index the wsi is bound to
+ * \param wsi: lws connection
+ *
+ * Only useful is LWS_MAX_SMP > 1
+ */
+LWS_VISIBLE LWS_EXTERN int
+lws_wsi_tsi(struct lws *wsi);
+
 /**
  * lws_set_wsi_user() - set the user data associated with the client connection
  * \param wsi: lws connection
diff --git a/lib/core-net/wsi.c b/lib/core-net/wsi.c
index 58c8e2bc6..2a8064edf 100644
--- a/lib/core-net/wsi.c
+++ b/lib/core-net/wsi.c
@@ -640,6 +640,13 @@ lws_wsi_user(struct lws *wsi)
 	return wsi->user_space;
 }
 
+int
+lws_wsi_tsi(struct lws *wsi)
+{
+	return wsi->tsi;
+}
+
+
 void
 lws_set_wsi_user(struct lws *wsi, void *data)
 {