diff --git a/fitsio/src/headers.rs b/fitsio/src/headers.rs
index c6ccbd6a..513be1a2 100644
--- a/fitsio/src/headers.rs
+++ b/fitsio/src/headers.rs
@@ -122,11 +122,11 @@ macro_rules! writes_key_impl_int {
     };
 }
 
-writes_key_impl_int!(i8, DataType::TSHORT);
+writes_key_impl_int!(i8, DataType::TSBYTE);
 writes_key_impl_int!(i16, DataType::TINT);
 writes_key_impl_int!(i32, DataType::TINT);
 writes_key_impl_int!(i64, DataType::TLONG);
-writes_key_impl_int!(u8, DataType::TUSHORT);
+writes_key_impl_int!(u8, DataType::TBYTE);
 writes_key_impl_int!(u16, DataType::TUINT);
 writes_key_impl_int!(u32, DataType::TUINT);
 writes_key_impl_int!(u64, DataType::TULONG);