diff --git a/server/go/camlistored/ui.go b/server/go/camlistored/ui.go
index c6d62a3bd..9cc428ec5 100644
--- a/server/go/camlistored/ui.go
+++ b/server/go/camlistored/ui.go
@@ -233,7 +233,16 @@ func (ui *UIHandler) serveUploadHelper(rw http.ResponseWriter, req *http.Request
 			http.Error(rw, "Multipart error: "+err.String(), 500)
 			break
 		}
-		br, err := schema.WriteFileFromReader(ui.Storage, part.FileName(), part)
+		fileName := part.FileName()
+		if fileName == "" {
+			continue
+		}
+		get, _ := http.ParseQuery(req.URL.RawQuery)
+		writeFn := schema.WriteFileFromReader
+		if len(get["rollsum"]) == 1 && get["rollsum"][0] == "1" {
+			writeFn = schema.WriteFileFromReaderRolling
+		}
+		br, err := writeFn(ui.Storage, fileName, part)
 
 		fmt.Fprintf(&buf, "filename=%q, formname=%q, br=<a href='./?b=%s'>%s</a>, err=%v\n", part.FileName(), part.FormName(), br, br, err)
 
diff --git a/server/go/camlistored/ui/index.html b/server/go/camlistored/ui/index.html
index e20f9dd3f..be4b0bbc7 100644
--- a/server/go/camlistored/ui/index.html
+++ b/server/go/camlistored/ui/index.html
@@ -36,15 +36,8 @@
     <form method="POST" id='uploadform' enctype="multipart/form-data">
       <input type="file" id="fileinput" multiple="true" name="file" disabled="true" />
       <input type="submit" id="filesubmit" value="Upload" disabled="true" />
+      <input type="checkbox" name="rollsum" id="chkrollsum" value="1" /> <label for="chkrollsum">Use rolling checksum for boundaries</label>
     </form>
-    <script>
-    if (disco && disco.uploadHelper) {
-        document.getElementById("uploadform").action = disco.uploadHelper;
-        document.getElementById("fileinput").disabled = false;
-        document.getElementById("filesubmit").disabled = false;
-    }
-    </script>
-
 
 </body>
 </html>
diff --git a/server/go/camlistored/ui/index.js b/server/go/camlistored/ui/index.js
index 50660de48..0ad1d2f6e 100644
--- a/server/go/camlistored/ui/index.js
+++ b/server/go/camlistored/ui/index.js
@@ -33,6 +33,26 @@ function indexOnLoad(e) {
     }
     btnNew.addEventListener("click", btnCreateNewPermanode);
     camliGetRecentlyUpdatedPermanodes({ success: indexBuildRecentlyUpdatedPermanodes });
+
+    if (disco && disco.uploadHelper) {
+        var uploadForm = document.getElementById("uploadform");
+        uploadform.action = disco.uploadHelper;
+        document.getElementById("fileinput").disabled = false;
+        document.getElementById("filesubmit").disabled = false;
+        var chkRollSum = document.getElementById("chkrollsum");
+        chkRollSum.addEventListener("change", function (e) {
+                                        if (chkRollSum.checked) {
+                                            if (disco.uploadHelper.indexOf("?") == -1) {
+                                                uploadform.action = disco.uploadHelper + "?rollsum=1";
+                                            } else {
+                                                uploadform.action = disco.uploadHelper + "&rollsum=1";
+                                            }
+                                        } else {
+                                            uploadform.action = disco.uploadHelper;
+                                        }
+                                    });
+    }
+
 }
 
 function indexBuildRecentlyUpdatedPermanodes(searchRes) {