diff --git a/src/util.js b/src/util.js
index 3968766..d097eb0 100644
--- a/src/util.js
+++ b/src/util.js
@@ -1,5 +1,3 @@
-const MAX_MERGED_BLOCK_SIZE = 30 * 2 ** 20 // 30 MB
-
 module.exports = {
   longToNumber(long) {
     if (
@@ -40,9 +38,9 @@ module.exports = {
 
   canMergeBlocks(block1, block2) {
     return (
+      block1.minv.blockPosition === block1.maxv.blockPosition &&
       block1.maxv.blockPosition === block2.minv.blockPosition &&
-      block2.maxv.blockPosition - block1.minv.blockPosition <=
-        MAX_MERGED_BLOCK_SIZE
+      block2.minv.blockPosition === block2.maxv.blockPosition
     )
   },
 }
diff --git a/test/csi.test.js b/test/csi.test.js
index 3ff0cef..8344500 100644
--- a/test/csi.test.js
+++ b/test/csi.test.js
@@ -47,7 +47,7 @@ describe('csi index', () => {
     let blocks = await ti.blocksForRange('1', 1, 4000)
     expect(blocks.length).toEqual(0)
     blocks = await ti.blocksForRange('1', 0, 2000046092)
-    expect(blocks.length).toEqual(1)
+    expect(blocks.length).toEqual(2)
     expect(blocks[0].minv.blockPosition).toEqual(0)
     expect(blocks[0].minv.dataPosition).toEqual(2560)
     // console.log( blocks );