diff --git a/src/core/ngx_radix_tree.c b/src/core/ngx_radix_tree.c
index b95cbc0..5b35d1e 100644
--- a/src/core/ngx_radix_tree.c
+++ b/src/core/ngx_radix_tree.c
@@ -60,7 +60,7 @@
      */
 
     if (preallocate == -1) {
-        switch (ngx_pagesize / sizeof(ngx_radix_tree_t)) {
+        switch (ngx_pagesize / sizeof(ngx_radix_node_t)) {
 
         /* amd64 */
         case 128: