diff --git a/src/openvpn/route.c b/src/openvpn/route.c
index 81ce867..8ea745d 100644
--- a/src/openvpn/route.c
+++ b/src/openvpn/route.c
@@ -1780,7 +1780,7 @@
         }
         else
         {
-            r6->network.s6_addr[byte--] &= (0xff << bits_to_clear);
+            r6->network.s6_addr[byte--] &= (uint8_t)(0xff << bits_to_clear);
             bits_to_clear = 0;
         }
     }