diff --git a/src/main/java/io/tarantool/driver/api/tuple/TarantoolNullField.java b/src/main/java/io/tarantool/driver/api/tuple/TarantoolNullField.java
index 35c681d3e..e93ada125 100644
--- a/src/main/java/io/tarantool/driver/api/tuple/TarantoolNullField.java
+++ b/src/main/java/io/tarantool/driver/api/tuple/TarantoolNullField.java
@@ -5,8 +5,6 @@
 import org.msgpack.value.Value;
 import org.msgpack.value.ValueFactory;
 
-import java.util.Objects;
-
 /**
  * Represents a field with empty value which serializes to {@code msgpack.NULL}
  *
@@ -44,6 +42,6 @@ public boolean equals(Object o) {
 
     @Override
     public int hashCode() {
-        return super.hashCode();
+        return TarantoolNullField.class.hashCode();
     }
 }
diff --git a/src/test/java/io/tarantool/driver/api/tuple/TarantoolNullFieldTest.java b/src/test/java/io/tarantool/driver/api/tuple/TarantoolNullFieldTest.java
index 217c53100..1a6afb0f5 100644
--- a/src/test/java/io/tarantool/driver/api/tuple/TarantoolNullFieldTest.java
+++ b/src/test/java/io/tarantool/driver/api/tuple/TarantoolNullFieldTest.java
@@ -20,7 +20,43 @@ public void test_hashCode_shouldReturnHashCode() {
     }
 
     @Test
-    public void test_AddNullFieldsToHashSet_shouldCreateHashSetWithTwoElements() {
+    public void test_toString_shouldReturnString() {
+        // given
+        TarantoolNullField nullField = new TarantoolNullField();
+
+        // when
+        String str = nullField.toString();
+
+        // then
+        assertNotNull(str);
+        assertFalse(str.isEmpty());
+        assertEquals(str, nullField.toString());
+    }
+
+    @Test
+    public void test_equals_shouldReturnTrue() {
+        // given
+        TarantoolNullField nullField1 = new TarantoolNullField();
+        TarantoolNullField nullField2 = new TarantoolNullField();
+
+        // then
+        assertEquals(nullField1, nullField1);
+        assertEquals(nullField1, nullField2);
+    }
+
+    @Test
+    public void test_equals_shouldReturnFalse() {
+        // given
+        TarantoolNullField nullField = new TarantoolNullField();
+        Object dummyObject = new Object() { };
+
+        // then
+        assertNotEquals(nullField, null);
+        assertNotEquals(nullField, dummyObject);
+    }
+
+    @Test
+    public void test_AddNullFieldsToHashSet_shouldCreateHashSetWithOneElements() {
         // given
         TarantoolNullField nullField1 = new TarantoolNullField();
         TarantoolNullField nullField2 = new TarantoolNullField();
@@ -31,7 +67,7 @@ public void test_AddNullFieldsToHashSet_shouldCreateHashSetWithTwoElements() {
         fieldsSet.add(nullField2);
 
         // then
-        assertEquals(2, fieldsSet.size());
+        assertEquals(1, fieldsSet.size());
         assertTrue(fieldsSet.contains(nullField1));
         assertTrue(fieldsSet.contains(nullField2));
     }