diff --git a/README.md b/README.md
index 4d8bc5a..3317b99 100644
--- a/README.md
+++ b/README.md
@@ -157,7 +157,18 @@ If the block could not be found, expect `err.code` to be `'ENOENT'`.
 
 Asynchronously returns the blocks whose content multihashes match the array
 `multihashes`.
-Returns an error (`err.code === 'ENOENT'`) if *any* the blocks do not exist.
+
+`blocks` is an object that maps each `multihash` to an object of the form
+
+```js
+{
+  err: Error
+  block: Block
+}
+```
+
+Expect `blocks[multihash].err.code === 'ENOENT'`  and `blocks[multihash].block
+=== null` if a block did not exist.
 
 *Does not guarantee atomicity.*
 
diff --git a/src/block-service.js b/src/block-service.js
index e4b6365..1f89101 100644
--- a/src/block-service.js
+++ b/src/block-service.js
@@ -52,18 +52,18 @@ function BlockService (ipfsRepo, exchange) {
       return callback(new Error('Invalid batch of multihashes'))
     }
 
-    const blocks = []
+    var results = {}
 
     async.each(multihashes, (multihash, next) => {
       this.getBlock(multihash, extension, (err, block) => {
-        if (err) { return next(err) }
-        if (block) {
-          blocks.push(block)
+        results[multihash] = {
+          err: err,
+          block: block
         }
         next()
       })
     }, (err) => {
-      callback(err, blocks)
+      callback(err, results)
     })
   }
 
diff --git a/test/block-service-test.js b/test/block-service-test.js
index e0c5ba9..880816a 100644
--- a/test/block-service-test.js
+++ b/test/block-service-test.js
@@ -93,7 +93,16 @@ module.exports = (repo) => {
 
         bs.getBlocks([b1.key, b2.key, b3.key], (err, blocks) => {
           expect(err).to.not.exist
-          expect(blocks).to.have.lengthOf(3)
+          expect(Object.keys(blocks)).to.have.lengthOf(3)
+          expect(blocks[b1.key]).to.exist
+          expect(blocks[b1.key].err).to.not.exist
+          expect(blocks[b1.key].block.data).to.deep.equal(b1.data)
+          expect(blocks[b2.key]).to.exist
+          expect(blocks[b2.key].err).to.not.exist
+          expect(blocks[b2.key].block.data).to.deep.equal(b2.data)
+          expect(blocks[b3.key]).to.exist
+          expect(blocks[b3.key].err).to.not.exist
+          expect(blocks[b3.key].block.data).to.deep.equal(b3.data)
           done()
         })
       })
@@ -108,8 +117,17 @@ module.exports = (repo) => {
         expect(err).to.not.exist
 
         bs.getBlocks([b1.key, b2.key, b3.key], (err, blocks) => {
-          expect(err).to.exist
-          expect(blocks).to.have.length.below(3)
+          expect(err).to.not.exist
+          expect(Object.keys(blocks)).to.have.lengthOf(3)
+          expect(blocks[b1.key]).to.exist
+          expect(blocks[b1.key].err).to.not.exist
+          expect(blocks[b1.key].block.data).to.deep.equal(b1.data)
+          expect(blocks[b2.key]).to.exist
+          expect(blocks[b2.key].err).to.exist
+          expect(blocks[b2.key].block).to.not.exist
+          expect(blocks[b3.key]).to.exist
+          expect(blocks[b3.key].err).to.not.exist
+          expect(blocks[b3.key].block.data).to.deep.equal(b3.data)
           done()
         })
       })