diff --git a/src/deflate/deflate.rs b/src/deflate/deflate.rs
index 38fa9314..e8044770 100644
--- a/src/deflate/deflate.rs
+++ b/src/deflate/deflate.rs
@@ -17,7 +17,7 @@ pub fn inflate(data: &[u8]) -> Result<Vec<u8>, String> {
     Ok(output)
 }
 
-pub fn deflate(data: &[u8], zc: u8, zm: u8, zs: u8, zw: u16) -> Result<Vec<u8>, String> {
+pub fn deflate(data: &[u8], zc: u8, zm: u8, zs: u8, zw: u8) -> Result<Vec<u8>, String> {
     let mut input = data.to_owned();
     let mut stream = super::stream::Stream::new_compress(zc as libc::c_int,
                                                          zw as libc::c_int,
diff --git a/src/deflate/stream.rs b/src/deflate/stream.rs
index 715722eb..9c95023a 100644
--- a/src/deflate/stream.rs
+++ b/src/deflate/stream.rs
@@ -62,19 +62,19 @@ impl Stream<Compress> {
 }
 
 impl<T: Direction> Stream<T> {
-    pub fn total_in(&self) -> u64 {
-        self.raw.total_in as u64
+    pub fn total_in(&self) -> usize {
+        self.raw.total_in as usize
     }
 
-    pub fn total_out(&self) -> u64 {
-        self.raw.total_out as u64
+    pub fn total_out(&self) -> usize {
+        self.raw.total_out as usize
     }
 }
 
 impl Stream<Decompress> {
     pub fn decompress_vec(&mut self, input: &mut [u8], output: &mut Vec<u8>) -> c_int {
-        self.raw.avail_in = (input.len() - self.total_in() as usize) as c_uint;
-        self.raw.avail_out = (output.capacity() - self.total_out() as usize) as c_uint;
+        self.raw.avail_in = (input.len() - self.total_in()) as c_uint;
+        self.raw.avail_out = (output.capacity() - self.total_out()) as c_uint;
 
         unsafe {
             self.raw.next_in = input.as_mut_ptr().offset(self.total_in() as isize);
diff --git a/src/lib.rs b/src/lib.rs
index ba21cbaf..d15ed1f9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -29,7 +29,7 @@ pub struct Options {
     pub compression: HashSet<u8>,
     pub memory: HashSet<u8>,
     pub strategies: HashSet<u8>,
-    pub window: u16,
+    pub window: u8,
     pub bit_depth_reduction: bool,
     pub color_type_reduction: bool,
     pub palette_reduction: bool,