diff --git a/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamLocalUriFetcher.java b/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamLocalUriFetcher.java
index 058d14a887..cd0c654324 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamLocalUriFetcher.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamLocalUriFetcher.java
@@ -22,18 +22,14 @@ class AttachmentStreamLocalUriFetcher implements DataFetcher<InputStream> {
   private final File             attachment;
   private final byte[]           key;
   private final Optional<byte[]> digest;
-  private final Optional<byte[]> incrementalDigest;
-  private final int              incrementalMacChunkSize;
   private final long             plaintextLength;
 
   private InputStream is;
 
-  AttachmentStreamLocalUriFetcher(File attachment, long plaintextLength, byte[] key, Optional<byte[]> digest, Optional<byte[]> incrementalDigest, int incrementalMacChunkSize) {
+  AttachmentStreamLocalUriFetcher(File attachment, long plaintextLength, byte[] key, Optional<byte[]> digest) {
     this.attachment              = attachment;
     this.plaintextLength         = plaintextLength;
     this.digest                  = digest;
-    this.incrementalDigest       = incrementalDigest;
-    this.incrementalMacChunkSize = incrementalMacChunkSize;
     this.key                     = key;
   }
 
@@ -41,7 +37,7 @@ class AttachmentStreamLocalUriFetcher implements DataFetcher<InputStream> {
   public void loadData(@NonNull Priority priority, @NonNull DataCallback<? super InputStream> callback) {
     try {
       if (!digest.isPresent()) throw new InvalidMessageException("No attachment digest!");
-      is = AttachmentCipherInputStream.createForAttachment(attachment, plaintextLength, key, digest.get(), incrementalDigest.orElse(null), incrementalMacChunkSize);
+      is = AttachmentCipherInputStream.createForAttachment(attachment, plaintextLength, key, digest.get(), null, 0);
       callback.onDataReady(is);
     } catch (IOException | InvalidMessageException e) {
       callback.onLoadFailed(e);
diff --git a/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamUriLoader.java b/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamUriLoader.java
index e00caf7f1a..cdb902f509 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamUriLoader.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/mms/AttachmentStreamUriLoader.java
@@ -20,7 +20,7 @@ public class AttachmentStreamUriLoader implements ModelLoader<AttachmentModel, I
 
   @Override
   public @Nullable LoadData<InputStream> buildLoadData(@NonNull AttachmentModel attachmentModel, int width, int height, @NonNull Options options) {
-    return new LoadData<>(attachmentModel, new AttachmentStreamLocalUriFetcher(attachmentModel.attachment, attachmentModel.plaintextLength, attachmentModel.key, attachmentModel.digest, attachmentModel.incrementalDigest, attachmentModel.incrementalMacChunkSize));
+    return new LoadData<>(attachmentModel, new AttachmentStreamLocalUriFetcher(attachmentModel.attachment, attachmentModel.plaintextLength, attachmentModel.key, attachmentModel.digest));
   }
 
   @Override
diff --git a/libsignal/service/src/main/java/org/whispersystems/signalservice/api/crypto/AttachmentCipherInputStream.java b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/crypto/AttachmentCipherInputStream.java
index 366a85a972..b07d66b95d 100644
--- a/libsignal/service/src/main/java/org/whispersystems/signalservice/api/crypto/AttachmentCipherInputStream.java
+++ b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/crypto/AttachmentCipherInputStream.java
@@ -53,6 +53,9 @@ public class AttachmentCipherInputStream extends FilterInputStream {
   private long    totalRead;
   private byte[]  overflowBuffer;
 
+  /**
+   * Passing in a null incrementalDigest and/or 0 for the chunk size at the call site disables incremental mac validation.
+   */
   public static InputStream createForAttachment(File file, long plaintextLength, byte[] combinedKeyMaterial, byte[] digest, byte[] incrementalDigest, int incrementalMacChunkSize)
       throws InvalidMessageException, IOException
   {