diff --git a/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy b/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
index ef33e8fd..d8836332 100644
--- a/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
+++ b/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
@@ -38,8 +38,8 @@ class ContentUploader extends Uploader {
         if (range.start >= length || range.end >= length)
             satisfiable = false
         if (satisfiable) {
-            int startPiece = length / range.start
-            int endPiece = length / range.end
+            int startPiece = range.start / (0x1 << pieceSize)
+            int endPiece = range.end / (0x1 << pieceSize)
             for (int i = startPiece; i < endPiece; i++)
                 satisfiable &= mesh.pieces.isDownloaded(i)
         }
diff --git a/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy b/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy
index c73cf988..d4758e37 100644
--- a/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy
+++ b/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy
@@ -85,16 +85,19 @@ public class UploadManager {
             
             Mesh mesh
             File file
+            int pieceSize
             if (downloader != null) {
                 mesh = meshManager.get(infoHash)
                 file = downloader.incompleteFile
+                pieceSize = downloader.pieceSizePow2
             } else {
                 SharedFile sharedFile = sharedFiles.iterator().next();
                 mesh = meshManager.getOrCreate(request.infoHash, sharedFile.NPieces)
                 file = sharedFile.file
+                pieceSize = sharedFile.pieceSize
             }
                 
-            Uploader uploader = new ContentUploader(file, request, e, mesh)
+            Uploader uploader = new ContentUploader(file, request, e, mesh, pieceSize)
             eventBus.publish(new UploadEvent(uploader : uploader))
             try {
                 uploader.respond()
@@ -207,16 +210,19 @@ public class UploadManager {
             
             Mesh mesh
             File file
+            int pieceSize
             if (downloader != null) {
                 mesh = meshManager.get(infoHash)
                 file = downloader.incompleteFile
+                pieceSize = downloader.pieceSizePow2
             } else {
                 SharedFile sharedFile = sharedFiles.iterator().next();
                 mesh = meshManager.getOrCreate(request.infoHash, sharedFile.NPieces)
                 file = sharedFile.file
+                pieceSize = sharedFile.pieceSize
             }
 
-            uploader = new ContentUploader(file, request, e, mesh)
+            uploader = new ContentUploader(file, request, e, mesh, pieceSize)
             eventBus.publish(new UploadEvent(uploader : uploader))
             try {
                 uploader.respond()