diff --git a/cloudflare/mock/durableObject.js b/cloudflare/mock/durableObject.js
index a5b37bd..46b4471 100644
--- a/cloudflare/mock/durableObject.js
+++ b/cloudflare/mock/durableObject.js
@@ -22,6 +22,13 @@ class DurableObjectState {
         return Promise.resolve(map);
       },
 
+      /**
+       * @override
+       *
+       * @param {string|!Object<string, *>} keys
+       * @param {*=} val
+       * @return {!Promise<void>}
+       */
       put: (keys, val) => {
         if (typeof keys === 'string')
           this.mem[keys] = val;
diff --git a/mina/merkleTree.js b/mina/merkleTree.js
index 335f1b5..6218f42 100644
--- a/mina/merkleTree.js
+++ b/mina/merkleTree.js
@@ -23,13 +23,13 @@ class MinaMerkleTree {
      * @const {!Object<string, Value>}
      */
     this.nodes = {};
-    /** @const {!Array<!bigint>} */
+    /** @const {!Array<Value>} */
     const zeros = Array(height + 1);
-    /** @const {!Array<!bigint>} */
+    /** @const {!Array<Value>} */
     zeros[height] = 0n;
     for (let i = height; i > 0; --i)
       zeros[i - 1] = poseidon([zeros[i], zeros[i]]);
-    /** @const {!Array<!bigint>} */
+    /** @const {!Array<Value>} */
     this.zeros = zeros;
   }
 
@@ -51,15 +51,15 @@ class MinaMerkleTree {
    * @return {Value} the root after insertion
    */
   setLeaf(key, val) {
-    /** @const {number} */
-    const h = this.height;
+    /** @type {number} */
+    let h = this.height;
     key = hex.toBinary(key).padStart(h, "0").slice(0, h);
-    for (; ;) {
+    for (; ; --h) {
       this.nodes[key] = val;
       if (!key) return val;
       const isLeft = key.charCodeAt(key.length - 1) == 48;
       key = key.slice(0, -1);
-      const sibling = this.getNode(key + +isLeft);
+      const sibling = this.nodes[key + +isLeft] || this.zeros[h];
       val = poseidon(isLeft ? [val, sibling] : [sibling, val]);
     }
   }
@@ -81,7 +81,7 @@ class MinaMerkleTree {
       key = key.slice(0, -1);
       witness[d] = {
         isLeft,
-        sibling: this.nodes[key] || this.zeros[h - d],
+        sibling: this.nodes[key + (+isLeft)] || this.zeros[h - d],
       };
     }
     return witness;
diff --git a/mina/test/merkleTree.compiled-test.js b/mina/test/merkleTree.compiled-test.js
index e503a0b..bab34ae 100644
--- a/mina/test/merkleTree.compiled-test.js
+++ b/mina/test/merkleTree.compiled-test.js
@@ -36,13 +36,66 @@ const testGetWitness = () => {
 
   const zeroWitness = tree.zeros.slice(1).reverse();
   assertArrayEq(
-    tree
-      .getWitness(HexKey("00000000"))
-      .map((/** @type {WitnessElem} */ w) => w.sibling),
+    tree.getWitness(HexKey("00000000")).map((/** @type {WitnessElem} */ w) => w.sibling),
     zeroWitness
   );
+
+  const t4 = new MinaMerkleTree(4);
+  t4.setLeaf(HexKey("E"), 31n);
+
+  assertArrayEq(
+    t4.getWitness(HexKey("F")).map((/** @type {WitnessElem} */ w) => w.sibling),
+    [31n, t4.zeros[3], t4.zeros[2], t4.zeros[1]]
+  );
+
+  t4.setLeaf(HexKey("D"), 30n);
+
+  assertArrayEq(
+    t4.getWitness(HexKey("F")).map((/** @type {WitnessElem} */ w) => w.sibling),
+    [31n, poseidon([0n, 30n]), t4.zeros[2], t4.zeros[1]]
+  );
+
+  t4.setLeaf(HexKey("B"), 28n);
+
+  assertArrayEq(
+    t4.getWitness(HexKey("F")).map((/** @type {WitnessElem} */ w) => w.sibling),
+    [31n, poseidon([0n, 30n]), poseidon([t4.zeros[3], poseidon([0n, 28n])]), t4.zeros[1]]
+  );
+
+  assertArrayEq(
+    t4.getWitness(HexKey("E")).map((/** @type {WitnessElem} */ w) => w.sibling),
+    [0n, poseidon([0n, 30n]), poseidon([t4.zeros[3], poseidon([0n, 28n])]), t4.zeros[1]]
+  );
+
+  assertArrayEq(
+    t4.getWitness(HexKey("E")).map((/** @type {WitnessElem} */ w) => w.isLeft),
+    [true, false, false, false]
+  );
 };
 
+// const testRoot = () => {
+//   const tree = new MerkleTree(2);
+
+//   tree.setLeaf("00", 12n);
+//   const root = tree.setLeaf("01", 13n);
+
+//   assertEq(tree.getNode(""), root);
+//   assertEq(
+//     tree.getNode(""),
+//     24761230160490995408576941661835661171884064004388554675853100205564068190570n
+//   );
+
+//   tree.setLeaf("10", 69n);
+//   const root2 = tree.setLeaf("11", 31n);
+
+//   assertEq(
+//     root2,
+//     19896916020666948695671743788555051064473578822640662440592176193110027392115n
+//   );
+//   assertEq(tree.getNode(""), root2);
+// };
+
 testSetGetLeaf();
 testNodeConsistency();
 testGetWitness();
+// testRoot();