diff --git a/psopacket/src/lib.rs b/psopacket/src/lib.rs
index 9e8df70..27f897a 100644
--- a/psopacket/src/lib.rs
+++ b/psopacket/src/lib.rs
@@ -447,7 +447,7 @@ fn generate_psomessage_impl(msg_cmd: u8, name: syn::Ident, attrs: &Vec<AttrType>
 
                 let mut fullbuf = Vec::new();
                 fullbuf.push(#msg_cmd);
-                fullbuf.push((buf.len() as u8 + 2) / 4);
+                fullbuf.push(((buf.len() + 2) / 4) as u8);
                 fullbuf.extend_from_slice(&mut buf);
 
                 fullbuf
diff --git a/src/lib.rs b/src/lib.rs
index 0b5e266..20409b2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -528,4 +528,21 @@ mod test {
             c: 5,
         });
     }
+
+    #[test]
+    fn test_pso_message_overflow() {
+        #[pso_message(0x23)]
+        struct Test {
+            b: [u32; 100],
+        };
+
+        let test = Test {
+            client: 1,
+            target: 2,
+            b: [23; 100],
+        };
+
+        let bytes = test.as_bytes();
+        assert!(bytes[1] == 101);
+    }
 }