diff --git a/src/com/fsck/k9/mail/filter/FixedLengthInputStream.java b/src/com/fsck/k9/mail/filter/FixedLengthInputStream.java
index 612b877ee..00e84a7cc 100644
--- a/src/com/fsck/k9/mail/filter/FixedLengthInputStream.java
+++ b/src/com/fsck/k9/mail/filter/FixedLengthInputStream.java
@@ -57,6 +57,15 @@ public class FixedLengthInputStream extends InputStream {
         return read(b, 0, b.length);
     }
 
+    @Override
+    public long skip(long n) throws IOException {
+        long d = mIn.skip(Math.min(n, available()));
+        if (d > 0) {
+            mCount += d;
+        }
+        return d;
+    }
+
     @Override
     public String toString() {
         return String.format("FixedLengthInputStream(in=%s, length=%d)", mIn.toString(), mLength);