diff --git a/src/int_property.rs b/src/int_property.rs
index 9e7343e..e90184c 100644
--- a/src/int_property.rs
+++ b/src/int_property.rs
@@ -3,29 +3,46 @@ use binrw::binrw;
 #[binrw]
 #[derive(Debug)]
 pub struct IntProperty {
-    /// In bytes
-    pub integer_size: u32,
-    #[br(pad_before = 5)]
+    #[bw(calc = 4)]
+    pub size_in_bytes: u32,
+    #[brw(pad_before = 5)]
     pub value: u32,
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
-    use binrw::BinRead;
+    use binrw::{BinRead, BinWrite};
     use std::io::Cursor;
 
     #[test]
-    fn zero() {
+    fn read_zero() {
         let data = [
             0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         ];
         let mut cursor = Cursor::new(data);
         let decoded = IntProperty::read_le(&mut cursor).unwrap();
-        assert_eq!(decoded.integer_size, 4);
         assert_eq!(decoded.value, 0);
     }
 
+    #[test]
+    fn write_zero() {
+        let expected_data: [u8; 13] = [
+            0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        ];
+        let property = IntProperty {
+            value: 0
+        };
+
+        let mut buffer: Vec<u8> = Vec::new();
+        {
+            let mut cursor = Cursor::new(&mut buffer);
+            property.write_le(&mut cursor).unwrap();
+        }
+
+        assert_eq!(expected_data, &buffer[..]);
+    }
+
     #[test]
     fn integer() {
         let data = [
@@ -33,7 +50,24 @@ mod tests {
         ];
         let mut cursor = Cursor::new(data);
         let decoded = IntProperty::read_le(&mut cursor).unwrap();
-        assert_eq!(decoded.integer_size, 4);
         assert_eq!(decoded.value, 4);
     }
+
+    #[test]
+    fn write_integer() {
+        let expected_data: [u8; 13] = [
+            0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
+        ];
+        let property = IntProperty {
+            value: 4
+        };
+
+        let mut buffer: Vec<u8> = Vec::new();
+        {
+            let mut cursor = Cursor::new(&mut buffer);
+            property.write_le(&mut cursor).unwrap();
+        }
+
+        assert_eq!(expected_data, &buffer[..]);
+    }
 }