diff --git a/Cargo.toml b/Cargo.toml
index 0808cff..a99239f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "mapped-file"
 description = "Construct a memory mapping over any file object"
 keywords = ["unix", "mmap", "generic", "file", "fd"]
-version = "0.0.3"
+version = "0.0.4"
 edition = "2021"
 repository="https://github.com/notflan/mapped-file"
 license="MIT"
diff --git a/src/lib.rs b/src/lib.rs
index 28d2998..870fe31 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -57,6 +57,9 @@ use err::{
 #[repr(transparent)]
 struct MappedSlice(UniqueSlice<u8>);
 
+unsafe impl Send for MappedSlice{}
+unsafe impl Sync for MappedSlice{}
+
 impl ops::Drop for MappedSlice
 {
     #[inline]
@@ -631,6 +634,24 @@ impl<T> BorrowMut<[u8]> for MappedFile<T>
     }
 }
 
+impl<T> AsRef<[u8]> for MappedFile<T>
+{
+    #[inline]
+    fn as_ref(&self) -> &[u8]
+    {
+	self.as_slice()
+    }
+}
+
+impl<T> AsMut<[u8]> for MappedFile<T>
+{
+    #[inline]
+    fn as_mut(&mut self) -> &mut [u8]
+    {
+	self.as_slice_mut()
+    }
+}
+
 impl<T> ops::Deref for MappedFile<T>
 {
     type Target=  [u8];