diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 5005b6b..c24ef17 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -1559,7 +1559,7 @@
 
     for ( ;; ) {
         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                       "proxy output chunk: %d", ngx_buf_size(cl->buf));
+                       "proxy output chunk: %O", ngx_buf_size(cl->buf));
 
         size += ngx_buf_size(cl->buf);
 
@@ -1917,7 +1917,7 @@
     }
 
     ngx_log_debug4(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                   "http proxy filter init s:%d h:%d c:%d l:%O",
+                   "http proxy filter init s:%ui h:%d c:%d l:%O",
                    u->headers_in.status_n, ctx->head, u->headers_in.chunked,
                    u->headers_in.content_length_n);
 
@@ -2125,7 +2125,7 @@
     }
 
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                   "http proxy chunked state %d, length %d",
+                   "http proxy chunked state %ui, length %O",
                    ctx->chunked.state, p->length);
 
     if (b) {
@@ -2299,7 +2299,7 @@
 
         for (cl = u->out_bufs; cl; cl = cl->next) {
             ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                           "http proxy in memory %p-%p %uz",
+                           "http proxy in memory %p-%p %O",
                            cl->buf->pos, cl->buf->last, ngx_buf_size(cl->buf));
 
             if (buf->last == cl->buf->pos) {