diff --git a/streams/src/test/java/org/apache/kafka/streams/state/internals/WindowStoreBuilderTest.java b/streams/src/test/java/org/apache/kafka/streams/state/internals/WindowStoreBuilderTest.java
index 6442da0d854..99ae792d344 100644
--- a/streams/src/test/java/org/apache/kafka/streams/state/internals/WindowStoreBuilderTest.java
+++ b/streams/src/test/java/org/apache/kafka/streams/state/internals/WindowStoreBuilderTest.java
@@ -17,7 +17,6 @@
 
 package org.apache.kafka.streams.state.internals;
 
-import java.time.Duration;
 import org.apache.kafka.common.config.TopicConfig;
 import org.apache.kafka.common.serialization.Serdes;
 import org.apache.kafka.common.utils.Bytes;
@@ -27,40 +26,37 @@ import org.apache.kafka.streams.state.StoreBuilder;
 import org.apache.kafka.streams.state.Stores;
 import org.apache.kafka.streams.state.WindowBytesStoreSupplier;
 import org.apache.kafka.streams.state.WindowStore;
-import org.easymock.EasyMockRunner;
-import org.easymock.Mock;
-import org.easymock.MockType;
 import org.hamcrest.CoreMatchers;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
 
+import java.time.Duration;
 import java.util.Collections;
 
-import static org.easymock.EasyMock.expect;
-import static org.easymock.EasyMock.replay;
-import static org.easymock.EasyMock.reset;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.core.IsInstanceOf.instanceOf;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThrows;
+import static org.mockito.Mockito.when;
 
-@RunWith(EasyMockRunner.class)
+@RunWith(MockitoJUnitRunner.StrictStubs.class)
 public class WindowStoreBuilderTest {
 
-    @Mock(type = MockType.NICE)
+    @Mock
     private WindowBytesStoreSupplier supplier;
-    @Mock(type = MockType.NICE)
+    @Mock
     private WindowStore<Bytes, byte[]> inner;
     private WindowStoreBuilder<String, String> builder;
 
     @Before
     public void setUp() {
-        expect(supplier.get()).andReturn(inner);
-        expect(supplier.name()).andReturn("name");
-        expect(supplier.metricsScope()).andReturn("metricScope");
-        replay(supplier);
+        when(supplier.get()).thenReturn(inner);
+        when(supplier.name()).thenReturn("name");
+        when(supplier.metricsScope()).thenReturn("metricScope");
 
         builder = new WindowStoreBuilder<>(
             supplier,
@@ -164,17 +160,6 @@ public class WindowStoreBuilderTest {
         assertThrows(NullPointerException.class, () -> new WindowStoreBuilder<>(null, Serdes.String(), Serdes.String(), new MockTime()));
     }
 
-    @Test
-    public void shouldThrowNullPointerIfKeySerdeIsNull() {
-        assertThrows(NullPointerException.class, () -> new WindowStoreBuilder<>(supplier, null, Serdes.String(), new MockTime()));
-    }
-
-    @Test
-    public void shouldThrowNullPointerIfValueSerdeIsNull() {
-        assertThrows(NullPointerException.class, () -> new WindowStoreBuilder<>(supplier, Serdes.String(),
-            null, new MockTime()));
-    }
-
     @Test
     public void shouldThrowNullPointerIfTimeIsNull() {
         assertThrows(NullPointerException.class, () -> new WindowStoreBuilder<>(supplier, Serdes.String(),
@@ -183,18 +168,7 @@ public class WindowStoreBuilderTest {
 
     @Test
     public void shouldThrowNullPointerIfMetricsScopeIsNull() {
-        reset(supplier);
-        expect(supplier.get()).andReturn(new RocksDBWindowStore(
-            new RocksDBSegmentedBytesStore(
-                "name",
-                null,
-                10L,
-                5L,
-                new WindowKeySchema()),
-            false,
-            1L));
-        expect(supplier.name()).andReturn("name");
-        replay(supplier);
+        when(supplier.metricsScope()).thenReturn(null);
 
         final Exception e = assertThrows(NullPointerException.class,
             () -> new WindowStoreBuilder<>(supplier, Serdes.String(), Serdes.String(), new MockTime()));