diff --git a/src/main/java/org/bitcoinj/core/AltcoinNetworkParameters.java b/src/main/java/org/altcoinj/core/AltcoinNetworkParameters.java
similarity index 91%
rename from src/main/java/org/bitcoinj/core/AltcoinNetworkParameters.java
rename to src/main/java/org/altcoinj/core/AltcoinNetworkParameters.java
index e0de2631..3bb36fab 100644
--- a/src/main/java/org/bitcoinj/core/AltcoinNetworkParameters.java
+++ b/src/main/java/org/altcoinj/core/AltcoinNetworkParameters.java
@@ -13,7 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.bitcoinj.core;
+package org.altcoinj.core;
+
+import org.bitcoinj.core.Block;
+import org.bitcoinj.core.Sha256Hash;
 
 /**
  *
diff --git a/src/main/java/org/bitcoinj/core/AltcoinSerializer.java b/src/main/java/org/altcoinj/core/AltcoinSerializer.java
similarity index 77%
rename from src/main/java/org/bitcoinj/core/AltcoinSerializer.java
rename to src/main/java/org/altcoinj/core/AltcoinSerializer.java
index dec3ab19..2cd57f28 100644
--- a/src/main/java/org/bitcoinj/core/AltcoinSerializer.java
+++ b/src/main/java/org/altcoinj/core/AltcoinSerializer.java
@@ -3,7 +3,13 @@
  * To change this template file, choose Tools | Templates
  * and open the template in the editor.
  */
-package org.bitcoinj.core;
+package org.altcoinj.core;
+
+import org.bitcoinj.core.AltcoinBlock;
+import org.bitcoinj.core.BitcoinSerializer;
+import org.bitcoinj.core.Block;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.ProtocolException;
 
 /**
  *
diff --git a/src/main/java/org/altcoinj/params/AbstractDogecoinParams.java b/src/main/java/org/altcoinj/params/AbstractDogecoinParams.java
index aefad16e..9797c376 100644
--- a/src/main/java/org/altcoinj/params/AbstractDogecoinParams.java
+++ b/src/main/java/org/altcoinj/params/AbstractDogecoinParams.java
@@ -20,7 +20,7 @@ import java.io.ByteArrayOutputStream;
 import java.math.BigInteger;
 import org.bitcoinj.core.AltcoinBlock;
 
-import org.bitcoinj.core.AltcoinNetworkParameters;
+import org.altcoinj.core.AltcoinNetworkParameters;
 import org.bitcoinj.core.Block;
 import org.bitcoinj.core.Coin;
 import static org.bitcoinj.core.Coin.COIN;
@@ -35,7 +35,7 @@ import org.bitcoinj.utils.MonetaryFormat;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import org.bitcoinj.core.AltcoinSerializer;
+import org.altcoinj.core.AltcoinSerializer;
 import org.bitcoinj.core.Sha256Hash;
 import org.bitcoinj.core.StoredBlock;
 import org.bitcoinj.core.Transaction;
diff --git a/src/main/java/org/bitcoinj/core/AltcoinBlock.java b/src/main/java/org/bitcoinj/core/AltcoinBlock.java
index b981b1cb..757dc1a0 100644
--- a/src/main/java/org/bitcoinj/core/AltcoinBlock.java
+++ b/src/main/java/org/bitcoinj/core/AltcoinBlock.java
@@ -17,6 +17,7 @@
 
 package org.bitcoinj.core;
 
+import org.altcoinj.core.AltcoinNetworkParameters;
 import com.google.common.base.Preconditions;
 
 import javax.annotation.Nullable;
diff --git a/src/main/java/org/bitcoinj/core/AuxPoW.java b/src/main/java/org/bitcoinj/core/AuxPoW.java
index 2f01f2c1..665843b2 100644
--- a/src/main/java/org/bitcoinj/core/AuxPoW.java
+++ b/src/main/java/org/bitcoinj/core/AuxPoW.java
@@ -18,6 +18,7 @@
 
 package org.bitcoinj.core;
 
+import org.altcoinj.core.AltcoinNetworkParameters;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
diff --git a/src/main/java/org/bitcoinj/core/MerkleBranch.java b/src/main/java/org/bitcoinj/core/MerkleBranch.java
index faa38844..c3ee5f8e 100644
--- a/src/main/java/org/bitcoinj/core/MerkleBranch.java
+++ b/src/main/java/org/bitcoinj/core/MerkleBranch.java
@@ -26,7 +26,6 @@ import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -97,7 +96,7 @@ public class MerkleBranch extends ChildMessage implements Serializable {
         cursor = offset + length;
     }
 
-    protected static int calcLength(byte[] buf, int offset) {
+    public static int calcLength(byte[] buf, int offset) {
         VarInt varint = new VarInt(buf, offset);
 
         return ((int) varint.value) * 4 + 4;
diff --git a/src/test/java/org/bitcoinj/core/DogecoinBlockTest.java b/src/test/java/org/bitcoinj/core/DogecoinBlockTest.java
index 19f6dd0d..6c65e353 100644
--- a/src/test/java/org/bitcoinj/core/DogecoinBlockTest.java
+++ b/src/test/java/org/bitcoinj/core/DogecoinBlockTest.java
@@ -5,6 +5,7 @@
  */
 package org.bitcoinj.core;
 
+import org.altcoinj.core.AltcoinSerializer;
 import java.io.IOException;
 import org.altcoinj.params.DogecoinMainNetParams;
 import static org.junit.Assert.assertArrayEquals;