diff --git a/core/src/main/groovy/com/muwire/core/download/DownloadSession.groovy b/core/src/main/groovy/com/muwire/core/download/DownloadSession.groovy
index 3a8cc586..7d8f9777 100644
--- a/core/src/main/groovy/com/muwire/core/download/DownloadSession.groovy
+++ b/core/src/main/groovy/com/muwire/core/download/DownloadSession.groovy
@@ -123,7 +123,9 @@ class DownloadSession {
 
             // parse X-Have if present
             if (headers.containsKey("X-Have")) { 
-                updateAvailablePieces(headers["X-Have"])
+                DataUtil.decodeXHave(headers["X-Have"]).each {
+                    available.add(it)
+                }
                 if (!available.contains(piece))
                     return true // try again next time
             } else {
@@ -224,16 +226,4 @@ class DownloadSession {
             totalRead += reads[idx]
         (int)(totalRead * 1000.0 / interval)
     }
-    
-    private void updateAvailablePieces(String xHave) {
-        byte [] availablePieces = Base64.decode(xHave)
-        availablePieces.eachWithIndex {b, i -> 
-            for (int j = 0; j < 8 ; j++) {
-                byte mask = 0x80 >>> j
-                if ((b & mask) == mask) {
-                    available.add(i * 8 + j)
-                }
-            }
-        }
-    }
 }
diff --git a/core/src/main/groovy/com/muwire/core/util/DataUtil.groovy b/core/src/main/groovy/com/muwire/core/util/DataUtil.groovy
index 26bd19d7..238fa871 100644
--- a/core/src/main/groovy/com/muwire/core/util/DataUtil.groovy
+++ b/core/src/main/groovy/com/muwire/core/util/DataUtil.groovy
@@ -95,4 +95,18 @@ class DataUtil {
         }
         Base64.encode(raw)
     }
+    
+    public static List<Integer> decodeXHave(String xHave) {
+        byte [] availablePieces = Base64.decode(xHave)
+        List<Integer> available = new ArrayList<>()
+        availablePieces.eachWithIndex {b, i ->
+            for (int j = 0; j < 8 ; j++) {
+                byte mask = 0x80 >>> j
+                if ((b & mask) == mask) {
+                    available.add(i * 8 + j)
+                }
+            }
+        }
+        available
+    }
 }