diff --git a/collections/motoko/src/ZhenyaHashmap.mo b/collections/motoko/src/ZhenyaHashmap.mo
index 7d2d20e9..4fd82303 100644
--- a/collections/motoko/src/ZhenyaHashmap.mo
+++ b/collections/motoko/src/ZhenyaHashmap.mo
@@ -5,11 +5,11 @@ import Iter "mo:base/Iter";
 import Option "mo:base/Option";
 import Random "random";
 import Profiling "../../../utils/motoko/Profiling";
-
+import Prim "mo:prim";
 actor {
     stable let profiling = Profiling.init();
-    
-    func f_hash(x : Nat64) : Nat32 = Hash.hash(Nat64.toNat x);
+
+    func f_hash(x : Nat64) : Nat32 = Prim.nat64ToNat32(x & 0xffffffff);
     let hash : HashMap.HashUtils<Nat64> = (f_hash, Nat64.equal);
     stable var map = HashMap.new<Nat64, Nat64>();
     let rand = Random.new(null, 42);
diff --git a/collections/motoko/src/hashmap.mo b/collections/motoko/src/hashmap.mo
index 92b70983..f8ae4fc1 100644
--- a/collections/motoko/src/hashmap.mo
+++ b/collections/motoko/src/hashmap.mo
@@ -9,7 +9,7 @@ import Profiling "../../../utils/motoko/Profiling";
 
 actor {
     stable let profiling = Profiling.init();
-    
+
     func hash(x: Nat64) : Nat32 = Hash.hash(Nat64.toNat x);
     var map = HashMap.HashMap<Nat64, Nat64>(0, Nat64.equal, hash);
     stable var stableMap: [(Nat64, Nat64)] = [];