diff --git a/src/main/java/com/google/crypto/tink/streamingaead/InputStreamDecrypter.java b/src/main/java/com/google/crypto/tink/streamingaead/InputStreamDecrypter.java
index 2778a3396..df3d77150 100644
--- a/src/main/java/com/google/crypto/tink/streamingaead/InputStreamDecrypter.java
+++ b/src/main/java/com/google/crypto/tink/streamingaead/InputStreamDecrypter.java
@@ -121,7 +121,7 @@ public synchronized int available() throws IOException {
   public synchronized int read() throws IOException {
     byte[] oneByte = new byte[1];
     if (read(oneByte) == 1) {
-      return oneByte[0];
+      return oneByte[0] & 0xff;
     }
     return -1;
   }