diff --git a/core/src/main/java/org/bitcoinj/utils/BlockFileLoader.java b/core/src/main/java/org/bitcoinj/utils/BlockFileLoader.java
index 97329c40..df6975cc 100644
--- a/core/src/main/java/org/bitcoinj/utils/BlockFileLoader.java
+++ b/core/src/main/java/org/bitcoinj/utils/BlockFileLoader.java
@@ -16,6 +16,8 @@
 
 package org.bitcoinj.utils;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
 import org.bitcoinj.core.Block;
 import org.bitcoinj.core.NetworkParameters;
 import org.bitcoinj.core.ProtocolException;
@@ -52,33 +54,45 @@ public class BlockFileLoader implements Iterable<Block>, Iterator<Block> {
     /**
      * Gets the list of files which contain blocks from Bitcoin Core.
      */
-    public static List<File> getReferenceClientBlockFileList() {
-        String defaultDataDir;
-        if (Utils.isWindows()) {
-            defaultDataDir = System.getenv("APPDATA") + "\\.bitcoin\\blocks\\";
-        } else if (Utils.isMac()) {
-            defaultDataDir = System.getProperty("user.home") + "/Library/Application Support/Bitcoin/blocks/";
-        } else if (Utils.isLinux()) {
-            defaultDataDir = System.getProperty("user.home") + "/.bitcoin/blocks/";
-        } else {
-            throw new RuntimeException("Unsupported system");
-        }
-
+    public static List<File> getReferenceClientBlockFileList(File blocksDir) {
+        checkArgument(blocksDir.isDirectory(), "%s is not a directory", blocksDir);
         List<File> list = new LinkedList<>();
         for (int i = 0; true; i++) {
-            File file = new File(defaultDataDir + String.format(Locale.US, "blk%05d.dat", i));
+            File file = new File(blocksDir, String.format(Locale.US, "blk%05d.dat", i));
             if (!file.exists())
                 break;
             list.add(file);
         }
         return list;
     }
-    
+
+    public static List<File> getReferenceClientBlockFileList() {
+        return getReferenceClientBlockFileList(defaultBlocksDir());
+    }
+
+    public static File defaultBlocksDir() {
+        final File defaultBlocksDir;
+        if (Utils.isWindows()) {
+            defaultBlocksDir = new File(System.getenv("APPDATA") + "\\.bitcoin\\blocks\\");
+        } else if (Utils.isMac()) {
+            defaultBlocksDir = new File(System.getProperty("user.home") + "/Library/Application Support/Bitcoin/blocks/");
+        } else if (Utils.isLinux()) {
+            defaultBlocksDir = new File(System.getProperty("user.home") + "/.bitcoin/blocks/");
+        } else {
+            throw new RuntimeException("Unsupported system");
+        }
+        return defaultBlocksDir;
+    }
+
     private Iterator<File> fileIt;
     private FileInputStream currentFileStream = null;
     private Block nextBlock = null;
     private NetworkParameters params;
-    
+
+    public BlockFileLoader(NetworkParameters params, File blocksDir) {
+        this(params, getReferenceClientBlockFileList(blocksDir));
+    }
+
     public BlockFileLoader(NetworkParameters params, List<File> files) {
         fileIt = files.iterator();
         this.params = params;