diff --git a/backend/src/event-handlers/rollup/compute-author-weights.js b/backend/src/event-handlers/rollup/compute-author-weights.js
index 1997f8d..c9d8b3c 100644
--- a/backend/src/event-handlers/rollup/compute-author-weights.js
+++ b/backend/src/event-handlers/rollup/compute-author-weights.js
@@ -3,17 +3,14 @@ const read = require('../../util/forum/read');
 const { matrixPools } = require('../../util/db');
 
 const computeAuthorWeights = async (batchItems_) => {
-  console.log('computeAuthorWeights starting');
   const weights = {};
   await Promise.each(batchItems_, async (postId) => {
     const post = await read(postId);
     const matrixPool = await matrixPools.get(postId);
-    console.log('batch item', { postId, post, matrixPool });
-    console.log('post.authors', post.authors);
     const { fee, result: { votePasses, quorumMet } } = matrixPool;
     post.authors.forEach(({ authorAddress, weightPPM }) => {
-      weights[authorAddress] = weights[authorAddress] ?? 0;
       if (votePasses && quorumMet) {
+        weights[authorAddress] = weights[authorAddress] ?? 0;
         // scale by matrix pool outcome and strength
         weights[authorAddress] += weightPPM * fee;
       }
@@ -21,18 +18,17 @@ const computeAuthorWeights = async (batchItems_) => {
       // TODO: Propagation via references
     });
   });
-  console.log('weights', weights);
   // Rescale author weights so they sum to 1000000
   const sumOfWeights = Object.values(weights).reduce((t, v) => t + v, 0);
+  if (!sumOfWeights) {
+    return [];
+  }
   const scaledWeights = Object.values(weights)
     .map((weight) => Math.floor((weight * 1000000) / sumOfWeights));
   const sumOfScaledWeights = scaledWeights.reduce((t, v) => t + v, 0);
   scaledWeights[0] += 1000000 - sumOfScaledWeights;
   const authors = Object.keys(weights)
     .map((authorAddress, i) => ({ authorAddress, weightPPM: scaledWeights[i] }));
-  console.log('computeAuthorWeights result', {
-    sumOfWeights, scaledWeights, sumOfScaledWeights, authors,
-  });
   return authors;
 };
 
diff --git a/backend/src/event-handlers/rollup/fetch-batch-items-info.js b/backend/src/event-handlers/rollup/fetch-batch-items-info.js
new file mode 100644
index 0000000..352c304
--- /dev/null
+++ b/backend/src/event-handlers/rollup/fetch-batch-items-info.js
@@ -0,0 +1,13 @@
+const { rollup } = require('../../util/contracts');
+
+const fetchBatchItemsInfo = async () => {
+  // Read from Rollup.items
+  const itemCount = await rollup.itemCount();
+  const promises = [];
+  for (let i = 0; i < itemCount; i += 1) {
+    promises.push(rollup.items(i));
+  }
+  return Promise.all(promises);
+};
+
+module.exports = fetchBatchItemsInfo;
diff --git a/backend/src/event-handlers/rollup/matrix-pools/initiate-matrix-pools.js b/backend/src/event-handlers/rollup/matrix-pools/initiate-matrix-pools.js
index 8876813..068e1ad 100644
--- a/backend/src/event-handlers/rollup/matrix-pools/initiate-matrix-pools.js
+++ b/backend/src/event-handlers/rollup/matrix-pools/initiate-matrix-pools.js
@@ -1,19 +1,9 @@
 const Promise = require('bluebird');
-const { rollup } = require('../../../util/contracts');
 const { matrixPools } = require('../../../util/db');
 const read = require('../../../util/forum/read');
 const initiateMatrixPool = require('./initiate');
 const { addBatchItem, getBatchItems } = require('../batch-items');
-
-const fetchBatchItemsInfo = async () => {
-  // Read from Rollup.items
-  const itemCount = await rollup.itemCount();
-  const promises = [];
-  for (let i = 0; i < itemCount; i += 1) {
-    promises.push(rollup.items(i));
-  }
-  return Promise.all(promises);
-};
+const fetchBatchItemsInfo = require('../fetch-batch-items-info');
 
 const initiateMatrixPools = async () => {
   const batchItemsInfo = await fetchBatchItemsInfo();
diff --git a/backend/src/event-handlers/rollup/submit-rollup.js b/backend/src/event-handlers/rollup/submit-rollup.js
index 4635d60..f704d59 100644
--- a/backend/src/event-handlers/rollup/submit-rollup.js
+++ b/backend/src/event-handlers/rollup/submit-rollup.js
@@ -8,13 +8,28 @@ const computeAuthorWeights = require('./compute-author-weights');
 const { wallet, rollup } = require('../../util/contracts');
 const { sendMatrixEvent } = require('../../matrix-bot');
 const { stakeRollupAvailability } = require('./utils');
+const fetchBatchItemsInfo = require('./fetch-batch-items-info');
 
 const submitRollup = async () => {
-  const batchItems = getBatchItems();
+  const availableBatchItems = getBatchItems();
+  const batchItems = [];
+  const batchItemsInfo = await fetchBatchItemsInfo();
+  for (let i = 0; i < batchItemsInfo.length; i += 1) {
+    const { postId } = batchItemsInfo[i];
+    if (availableBatchItems.includes(postId)) {
+      batchItems.push(postId);
+    } else {
+      // Batch items have to be submitted in the correct order, with no gaps
+      break;
+    }
+  }
   if (!batchItems.length) {
     return { batchItems: [] };
   }
   const authors = await computeAuthorWeights(batchItems);
+  if (!authors.length) {
+    return { batchItems: [] };
+  }
   // TODO: Compute citations as aggregate of the citations of posts in the batch
   const citations = [];
   const content = `Batch of ${batchItems.length} items`;