diff --git a/src/http/modules/ngx_http_geo_module.c b/src/http/modules/ngx_http_geo_module.c
index af061af..e643804 100644
--- a/src/http/modules/ngx_http_geo_module.c
+++ b/src/http/modules/ngx_http_geo_module.c
@@ -966,7 +966,7 @@
 
     warn = 0;
 
-    for (n = start; n <= end; n += 0x10000) {
+    for (n = start; n <= end; n = (n + 0x10000) & 0xffff0000) {
 
         h = n >> 16;
 
diff --git a/src/stream/ngx_stream_geo_module.c b/src/stream/ngx_stream_geo_module.c
index 3bdeff7..1ee0154 100644
--- a/src/stream/ngx_stream_geo_module.c
+++ b/src/stream/ngx_stream_geo_module.c
@@ -916,7 +916,7 @@
 
     warn = 0;
 
-    for (n = start; n <= end; n += 0x10000) {
+    for (n = start; n <= end; n = (n + 0x10000) & 0xffff0000) {
 
         h = n >> 16;