diff --git a/test/core/end2end/fixtures/proxy.c b/test/core/end2end/fixtures/proxy.c
index f6e01ec41c5..7f10649fa69 100644
--- a/test/core/end2end/fixtures/proxy.c
+++ b/test/core/end2end/fixtures/proxy.c
@@ -282,6 +282,8 @@ static void on_p2s_recv_msg(void *arg, int success) {
     err = grpc_call_start_batch(pc->c2p, &op, 1,
                                 new_closure(on_c2p_sent_message, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
+  } else {
+    grpc_byte_buffer_destroy(pc->p2s_msg);
   }
   unrefpc(pc, "on_p2s_recv_msg");
 }