diff --git a/src/pxar/decoder.rs b/src/pxar/decoder.rs
index df636501..9b07aed7 100644
--- a/src/pxar/decoder.rs
+++ b/src/pxar/decoder.rs
@@ -33,7 +33,7 @@ impl <R: Read + Seek> ReadSeek for R {}
 
 // This one needs Read+Seek
 pub struct Decoder {
-    inner: SequentialDecoder<Box<dyn ReadSeek>>,
+    inner: SequentialDecoder<Box<dyn ReadSeek + Send>>,
     root_start: u64,
     root_end: u64,
 }
@@ -42,15 +42,15 @@ const HEADER_SIZE: u64 = std::mem::size_of::<PxarHeader>() as u64;
 const GOODBYE_ITEM_SIZE: u64 = std::mem::size_of::<PxarGoodbyeItem>() as u64;
 
 impl Decoder {
-    pub fn new<R: Read + Seek + 'static>(mut reader: R) -> Result<Self, Error> {
+    pub fn new<R: Read + Seek + Send + 'static>(mut reader: R) -> Result<Self, Error> {
         let root_end = reader.seek(SeekFrom::End(0))?;
-        let boxed_reader: Box<dyn ReadSeek + 'static> = Box::new(reader);
+        let boxed_reader: Box<dyn ReadSeek + 'static + Send> = Box::new(reader);
         let inner = SequentialDecoder::new(boxed_reader, super::flags::DEFAULT);
   
         Ok(Self { inner, root_start: 0, root_end })
     }
 
-    pub fn set_callback<F: Fn(&Path) -> Result<(), Error> + 'static>(&mut self, callback: F ) {
+    pub fn set_callback<F: Fn(&Path) -> Result<(), Error> + Send + 'static>(&mut self, callback: F ) {
         self.inner.set_callback(callback);
     }
 
diff --git a/src/pxar/sequential_decoder.rs b/src/pxar/sequential_decoder.rs
index 6364fe5a..012991a6 100644
--- a/src/pxar/sequential_decoder.rs
+++ b/src/pxar/sequential_decoder.rs
@@ -35,7 +35,7 @@ pub struct SequentialDecoder<R: Read> {
     feature_flags: u64,
     allow_existing_dirs: bool,
     skip_buffer: Vec<u8>,
-    callback: Option<Box<dyn Fn(&Path) -> Result<(), Error>>>,
+    callback: Option<Box<dyn Fn(&Path) -> Result<(), Error> + Send>>,
 }
 
 const HEADER_SIZE: u64 = std::mem::size_of::<PxarHeader>() as u64;
@@ -57,7 +57,7 @@ impl<R: Read> SequentialDecoder<R> {
         }
     }
 
-    pub fn set_callback<F: Fn(&Path) -> Result<(), Error> + 'static>(&mut self, callback: F ) {
+    pub fn set_callback<F: Fn(&Path) -> Result<(), Error> + Send + 'static>(&mut self, callback: F ) {
         self.callback = Some(Box::new(callback));
     }