diff --git a/ssz_serialization/merkleization.nim b/ssz_serialization/merkleization.nim
index 91f8945..207a0be 100644
--- a/ssz_serialization/merkleization.nim
+++ b/ssz_serialization/merkleization.nim
@@ -1413,13 +1413,13 @@ func hash_tree_root*(
     when indices.len == 1 and indices[0] == 1.GeneralizedIndex:
       ResultType.ok([hash_tree_root(x)])
     else:
-      var roots {.noinit.}: array[indices.len, Digest]
       const
         loopOrder = merkleizationLoopOrder(indices)
         v = validateIndices(indices, loopOrder)
       when v.isErr:
         ResultType.err(v.error)
       else:
+        var roots {.noinit.}: array[indices.len, Digest]
         const slice = 0 ..< loopOrder.len
         let w = hash_tree_root_multi(x, indices, roots, loopOrder, slice)
         if w.isErr:
diff --git a/tests/test_merkleization_types.nim b/tests/test_merkleization_types.nim
index ac8293d..feda94f 100644
--- a/tests/test_merkleization_types.nim
+++ b/tests/test_merkleization_types.nim
@@ -8,11 +8,14 @@
 {.used.}
 
 import
-  std/[sequtils, tables],
+  std/tables,
+  results,
   unittest2,
-  stew/[endians2, results],
+  stew/endians2,
   ../ssz_serialization/merkleization
 
+from std/sequtils import mapIt
+
 func d(x: openArray[byte]): Digest =
   result.data[0 ..< x.len] = x
 
@@ -97,8 +100,7 @@ let
     u: E(x: false, y: true),
     v: (a: false, b: true),
     w: (a: E(x: false, y: true), b: E(x: true, y: false), c: true),
-    x: HashArray[2, E](data: array[2, E](
-      [E(x: false, y: true), E(x: true, y: false)])),
+    x: HashArray[2, E](data: [E(x: false, y: true), E(x: true, y: false)]),
     y: HashList[E, 2].init(
       @[E(x: false, y: true), E(x: true, y: false)]),
     z: HashList[E, 2].init(@[]))