There's no need to normalize address returned by ngx_ptocidr().
diff --git a/src/http/modules/ngx_http_geo_module.c b/src/http/modules/ngx_http_geo_module.c
index 1170cb3..24091bf 100644
--- a/src/http/modules/ngx_http_geo_module.c
+++ b/src/http/modules/ngx_http_geo_module.c
@@ -998,7 +998,7 @@
         /* rc == NGX_BUSY */
 
         old = (ngx_http_variable_value_t *)
-              ngx_radix32tree_find(ctx->tree, cidr.u.in.addr & cidr.u.in.mask);
+              ngx_radix32tree_find(ctx->tree, cidr.u.in.addr);
 
         ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                 "duplicate network \"%V\", value: \"%v\", old value: \"%v\"",