diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 3cca57cf5..3459d2726 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -2526,6 +2526,7 @@ ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
 
     if (r != r->main && r->post_subrequest) {
         rc = r->post_subrequest->handler(r, r->post_subrequest->data, rc);
+        r->post_subrequest = NULL;
     }
 
     if (rc == NGX_ERROR