diff --git a/src/stream/zio/reader.rs b/src/stream/zio/reader.rs
index 4214bbd5..659a74d8 100644
--- a/src/stream/zio/reader.rs
+++ b/src/stream/zio/reader.rs
@@ -63,7 +63,13 @@ impl<R, D> Reader<R, D> {
     }
 
     /// Returns the inner reader.
-    pub fn into_inner(self) -> R {
+    pub fn into_inner(mut self) -> R
+    where
+        R: BufRead,
+        D: Operation,
+    {
+        // Ensure the input buffers have been flushed by reading to a zero-length buffer.
+        let _ = self.read(&mut [0; 0]);
         self.reader
     }