diff --git a/src/com/fsck/k9/mail/filter/PeekableInputStream.java b/src/com/fsck/k9/mail/filter/PeekableInputStream.java
index 9ef98abe3..a6e4868d7 100644
--- a/src/com/fsck/k9/mail/filter/PeekableInputStream.java
+++ b/src/com/fsck/k9/mail/filter/PeekableInputStream.java
@@ -30,7 +30,7 @@ public class PeekableInputStream extends InputStream {
 
     public int peek() throws IOException {
         if (!mPeeked) {
-            mPeekedByte = read();
+            mPeekedByte = mIn.read();
             mPeeked = true;
         }
         return mPeekedByte;