diff --git a/packets/src/lib.rs b/packets/src/lib.rs
index ba4f3a2..a5f7da4 100644
--- a/packets/src/lib.rs
+++ b/packets/src/lib.rs
@@ -540,7 +540,7 @@ impl IPv4Packet {
             + dest_upper as u32
             + dest_lower as u32;
 
-        let checksum: u16 = ((checksum_part & 0xFFFF) + (checksum_part >> 16))
+        let checksum: u16 = (((checksum_part & 0xFFFF) + (checksum_part >> 16)) & 0xFFFF)
             .try_into()
             .unwrap();