diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index 798e668aed9..ecb3e49c98d 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -109,8 +109,9 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
     bool sent_initial_metadata = s->sent_initial_metadata;
     bool now_writing = false;
 
-    gpr_log(GPR_DEBUG, "W:%d: sim=%d ann=%d fcb_len=%d (t,s)-win=%d,%d",
-            (int)s->id, sent_initial_metadata, (int)s->announce_window,
+    gpr_log(GPR_DEBUG, "W:%d:%s: sim=%d ann=%d fcb_len=%d (t,s)-win=%d,%d",
+            (int)s->id, t->is_client ? "client" : "server",
+            sent_initial_metadata, (int)s->announce_window,
             (int)s->flow_controlled_buffer.length, (int)t->outgoing_window,
             (int)s->outgoing_window);