diff --git a/runtime/ecma_string-inl.h b/runtime/ecma_string-inl.h
index d0b2d766a185ae19658410a32b190382597b7086..70690920fb6b9e2596213c0a3516ed54c29ec5c3 100644
--- a/runtime/ecma_string-inl.h
+++ b/runtime/ecma_string-inl.h
@@ -43,6 +43,7 @@ inline EcmaString *EcmaString::CreateEmptyString(const EcmaVM *vm)
     auto string = vm->GetFactory()->AllocNonMovableStringObject(EcmaString::SIZE);
     string->SetLength(0, GetCompressedStringsEnabled());
     string->SetRawHashcode(0);
+    ASSERT(string->GetStringHashCode() == 0U);
     return string;
 }
 
@@ -124,6 +125,7 @@ inline EcmaString *EcmaString::AllocStringObject(size_t length, bool compressed,
                       : reinterpret_cast<EcmaString *>(vm->GetFactory()->AllocStringObject(size));
     string->SetLength(length, compressed);
     string->SetRawHashcode(0);
+    ASSERT(string->GetStringHashCode() == 0U);
     return reinterpret_cast<EcmaString *>(string);
 }
 
diff --git a/runtime/ecma_string.cpp b/runtime/ecma_string.cpp
index 5d39282763a8d5f43420837dee511e886a8fb34d..3156d4e306737ae28cddd6b3ab1732184cb535ee 100644
--- a/runtime/ecma_string.cpp
+++ b/runtime/ecma_string.cpp
@@ -375,6 +375,23 @@ bool EcmaString::StringCopy(Span<T> &dst, size_t dst_max, Span<const T> &src, si
     return true;
 }
 
+template <class T>
+static int32_t ComputeHashForData(const T *data, size_t size)
+{
+    uint32_t hash = 0;
+#if defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wignored-attributes"
+    Span<const T> sp(data, size);
+#pragma GCC diagnostic pop
+#endif
+    for (auto c : sp) {
+        constexpr size_t SHIFT = 5;
+        hash = (hash << SHIFT) - hash + c;
+    }
+    return static_cast<int32_t>(hash) & MarkWord::HASH_MASK;
+}
+
 static int32_t ComputeHashForUtf8(const uint8_t *utf8_data, size_t utf8_len)
 {
     if (utf8_data == nullptr) {
@@ -385,7 +402,7 @@ static int32_t ComputeHashForUtf8(const uint8_t *utf8_data, size_t utf8_len)
         constexpr size_t SHIFT = 5;
         hash = (hash << SHIFT) - hash + *utf8_data++;  // NOLINT(cppcoreguidelines-pro-bounds-pointer-arithmetic)
     }
-    return static_cast<int32_t>(hash);
+    return static_cast<int32_t>(hash) & MarkWord::HASH_MASK;
 }
 
 uint32_t EcmaString::ComputeHashcode() const
diff --git a/runtime/ecma_string.h b/runtime/ecma_string.h
index bdd17113cbbb7507f19ce7fd134556189702391f..4293332d65d1e54d7298be00308d082345238d82 100644
--- a/runtime/ecma_string.h
+++ b/runtime/ecma_string.h
@@ -30,23 +30,6 @@ template <typename T>
 class JSHandle;
 class EcmaVM;
 
-template <class T>
-static int32_t ComputeHashForData(const T *data, size_t size)
-{
-    uint32_t hash = 0;
-#if defined(__GNUC__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wignored-attributes"
-    Span<const T> sp(data, size);
-#pragma GCC diagnostic pop
-#endif
-    for (auto c : sp) {
-        constexpr size_t SHIFT = 5;
-        hash = (hash << SHIFT) - hash + c;
-    }
-    return static_cast<int32_t>(hash);
-}
-
 class EcmaString : public TaggedObject {
 public:
     static EcmaString *Cast(ObjectHeader *object);
@@ -233,11 +216,15 @@ public:
 
     uint32_t GetHashcode()
     {
-        uint32_t hashcode = GetRawHashcode();
+        uint32_t hashcode = this->GetStringHashCode();
         if (hashcode == 0) {
             hashcode = ComputeHashcode();
             SetRawHashcode(hashcode);
+            this->SaveStringHashCode(hashcode);
+        } else {
+            ASSERT(hashcode == ComputeHashcode());
         }
+        ASSERT((hashcode & (~MarkWord::HASH_MASK)) == 0U);
         return hashcode;
     }
 
@@ -309,6 +296,7 @@ private:
         return reinterpret_cast<uint8_t *>(GetData());
     }
 
+    static uint32_t ConvertHashCode(uint32_t hashcode);
     uint32_t ComputeHashcode() const;
     static void CopyUtf16AsUtf8(const uint16_t *utf16_from, uint8_t *utf8_to, uint32_t utf16_len);