diff --git a/src/os/unix/ngx_linux_sendfile_chain.c b/src/os/unix/ngx_linux_sendfile_chain.c
index eb15c7a..ab2a3cf 100644
--- a/src/os/unix/ngx_linux_sendfile_chain.c
+++ b/src/os/unix/ngx_linux_sendfile_chain.c
@@ -254,6 +254,10 @@
 #else
             offset = (int32_t) file->file_pos;
 #endif
+
+            ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                           "sendfile: @%O %uz", file->file_pos, file_size);
+
             rc = sendfile(c->fd, file->file->fd, &offset, file_size);
 
             if (rc == -1) {