diff --git a/src/os/unix/ngx_udp_sendmsg_chain.c b/src/os/unix/ngx_udp_sendmsg_chain.c
index 78b497ea0..b29b8d318 100644
--- a/src/os/unix/ngx_udp_sendmsg_chain.c
+++ b/src/os/unix/ngx_udp_sendmsg_chain.c
@@ -398,15 +398,6 @@ eintr:
 
     n = sendmsg(c->fd, msg, flags);
 
-#if (NGX_DEBUG)
-    for (i = 0, size = 0; i < (size_t) msg->msg_iovlen; i++) {
-        size += msg->msg_iov[i].iov_len;
-    }
-
-    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                   "sendmsg: %z of %uz", n, size);
-#endif
-
     if (n == -1) {
         err = ngx_errno;
 
@@ -428,5 +419,14 @@ eintr:
         }
     }
 
+#if (NGX_DEBUG)
+    for (i = 0, size = 0; i < (size_t) msg->msg_iovlen; i++) {
+        size += msg->msg_iov[i].iov_len;
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "sendmsg: %z of %uz", n, size);
+#endif
+
     return n;
 }