diff --git a/luprex/cpp/drv/driver-common.cpp b/luprex/cpp/drv/driver-common.cpp
index 78d81ef9..816d3073 100644
--- a/luprex/cpp/drv/driver-common.cpp
+++ b/luprex/cpp/drv/driver-common.cpp
@@ -449,8 +449,10 @@ class Driver {
             }
             if (chan.nbytes == 0) {
                 if (engw.get_channel_released(&engw, chan.chid)) {
-                    close_channel(chan, "");
-                    any_released = true;
+                    if (BIO_pending(chan.send_bio) == 0) {
+                        close_channel(chan, "");
+                        any_released = true;
+                    }
                 }
             }
         }