--- a/src/http/ngx_http_variables.c
+++ b/src/http/ngx_http_variables.c
@@ -1316,6 +1316,8 @@ static ngx_int_t
 ngx_http_variable_sent_location(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data)
 {
+    ngx_str_t  name;
+
     if (r->headers_out.location) {
         v->len = r->headers_out.location->value.len;
         v->valid = 1;
@@ -1326,7 +1328,10 @@ ngx_http_variable_sent_location(ngx_http
         return NGX_OK;
     }
 
-    return ngx_http_variable_unknown_header(v, (ngx_str_t *) data,
+    name.len = sizeof("sent_http_location") - 1;
+    name.data = (u_char *) "sent_http_location";
+
+    return ngx_http_variable_unknown_header(v, &name,
                                             &r->headers_out.headers.part,
                                             sizeof("sent_http_") - 1);
 }