diff --git a/src/test/java/org/springframework/data/elasticsearch/config/nested/EnableNestedElasticsearchRepositoriesTests.java b/src/test/java/org/springframework/data/elasticsearch/config/nested/EnableNestedElasticsearchRepositoriesTests.java
index 501447152..ac45a4f30 100644
--- a/src/test/java/org/springframework/data/elasticsearch/config/nested/EnableNestedElasticsearchRepositoriesTests.java
+++ b/src/test/java/org/springframework/data/elasticsearch/config/nested/EnableNestedElasticsearchRepositoriesTests.java
@@ -15,7 +15,7 @@
  */
 package org.springframework.data.elasticsearch.config.nested;
 
-import static org.junit.Assert.*;
+import static org.assertj.core.api.Assertions.*;
 import static org.springframework.data.elasticsearch.annotations.FieldType.*;
 
 import lombok.Builder;
@@ -70,7 +70,7 @@ public class EnableNestedElasticsearchRepositoriesTests {
 
 	@Test
 	public void hasNestedRepository() {
-		assertNotNull(nestedRepository);
+		assertThat(nestedRepository).isNotNull();
 	}
 
 	@Data
diff --git a/src/test/java/org/springframework/data/elasticsearch/core/aggregation/AggregatedPageImplTest.java b/src/test/java/org/springframework/data/elasticsearch/core/aggregation/AggregatedPageImplTest.java
index 99bdacb6e..7090949c0 100644
--- a/src/test/java/org/springframework/data/elasticsearch/core/aggregation/AggregatedPageImplTest.java
+++ b/src/test/java/org/springframework/data/elasticsearch/core/aggregation/AggregatedPageImplTest.java
@@ -15,7 +15,7 @@
  */
 package org.springframework.data.elasticsearch.core.aggregation;
 
-import static org.junit.Assert.*;
+import static org.assertj.core.api.Assertions.*;
 
 import java.util.Arrays;
 
@@ -34,9 +34,9 @@ public class AggregatedPageImplTest {
 	public void constructFacetedPageWithPageable() {
 		Page<String> page = new AggregatedPageImpl<>(Arrays.asList("Test", "Test 2"), PageRequest.of(0, 2), 10);
 
-		assertEquals(10, page.getTotalElements());
-		assertEquals(2, page.getNumberOfElements());
-		assertEquals(2, page.getSize());
-		assertEquals(5, page.getTotalPages());
+		assertThat(page.getTotalElements()).isEqualTo(10);
+		assertThat(page.getNumberOfElements()).isEqualTo(2);
+		assertThat(page.getSize()).isEqualTo(2);
+		assertThat(page.getTotalPages()).isEqualTo(5);
 	}
 }
diff --git a/src/test/java/org/springframework/data/elasticsearch/core/convert/DateTimeConvertersTests.java b/src/test/java/org/springframework/data/elasticsearch/core/convert/DateTimeConvertersTests.java
index 44898b82c..1501f9155 100644
--- a/src/test/java/org/springframework/data/elasticsearch/core/convert/DateTimeConvertersTests.java
+++ b/src/test/java/org/springframework/data/elasticsearch/core/convert/DateTimeConvertersTests.java
@@ -15,13 +15,14 @@
  */
 package org.springframework.data.elasticsearch.core.convert;
 
+import static org.assertj.core.api.Assertions.*;
+
 import java.util.Calendar;
 import java.util.TimeZone;
 
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
 import org.joda.time.LocalDateTime;
-import org.junit.Assert;
 import org.junit.Test;
 
 /**
@@ -32,32 +33,32 @@ public class DateTimeConvertersTests {
 
 	@Test
 	public void testJodaDateTimeConverterWithNullValue() {
-		Assert.assertNull(DateTimeConverters.JodaDateTimeConverter.INSTANCE.convert(null));
+		assertThat(DateTimeConverters.JodaDateTimeConverter.INSTANCE.convert(null)).isNull();
 	}
 
 	@Test
 	public void testJodaDateTimeConverter() {
 		DateTime dateTime = new DateTime(2013, 1, 24, 6, 35, 0, DateTimeZone.UTC);
-		Assert.assertEquals("2013-01-24T06:35:00.000Z",
-				DateTimeConverters.JodaDateTimeConverter.INSTANCE.convert(dateTime));
+		assertThat(DateTimeConverters.JodaDateTimeConverter.INSTANCE.convert(dateTime))
+				.isEqualTo("2013-01-24T06:35:00.000Z");
 	}
 
 	@Test
 	public void testJodaLocalDateTimeConverterWithNullValue() {
-		Assert.assertNull(DateTimeConverters.JodaLocalDateTimeConverter.INSTANCE.convert(null));
+		assertThat(DateTimeConverters.JodaLocalDateTimeConverter.INSTANCE.convert(null)).isNull();
 	}
 
 	@Test
 	public void testJodaLocalDateTimeConverter() {
 		LocalDateTime dateTime = new LocalDateTime(new DateTime(2013, 1, 24, 6, 35, 0, DateTimeZone.UTC).getMillis(),
 				DateTimeZone.UTC);
-		Assert.assertEquals("2013-01-24T06:35:00.000Z",
-				DateTimeConverters.JodaLocalDateTimeConverter.INSTANCE.convert(dateTime));
+		assertThat(DateTimeConverters.JodaLocalDateTimeConverter.INSTANCE.convert(dateTime))
+				.isEqualTo("2013-01-24T06:35:00.000Z");
 	}
 
 	@Test
 	public void testJavaDateConverterWithNullValue() {
-		Assert.assertNull(DateTimeConverters.JavaDateConverter.INSTANCE.convert(null));
+		assertThat(DateTimeConverters.JavaDateConverter.INSTANCE.convert(null)).isNull();
 	}
 
 	@Test
@@ -67,7 +68,7 @@ public class DateTimeConvertersTests {
 		calendar.setTimeZone(TimeZone.getTimeZone("UTC"));
 		calendar.setTimeInMillis(dateTime.getMillis());
 
-		Assert.assertEquals("2013-01-24T06:35:00.000Z",
-				DateTimeConverters.JavaDateConverter.INSTANCE.convert(calendar.getTime()));
+		assertThat(DateTimeConverters.JavaDateConverter.INSTANCE.convert(calendar.getTime()))
+				.isEqualTo("2013-01-24T06:35:00.000Z");
 	}
 }
diff --git a/src/test/java/org/springframework/data/elasticsearch/repositories/dynamicindex/DynamicIndexEntityTests.java b/src/test/java/org/springframework/data/elasticsearch/repositories/dynamicindex/DynamicIndexEntityTests.java
index b08adc9ec..013f56e16 100644
--- a/src/test/java/org/springframework/data/elasticsearch/repositories/dynamicindex/DynamicIndexEntityTests.java
+++ b/src/test/java/org/springframework/data/elasticsearch/repositories/dynamicindex/DynamicIndexEntityTests.java
@@ -15,12 +15,13 @@
  */
 package org.springframework.data.elasticsearch.repositories.dynamicindex;
 
-import static org.junit.Assert.*;
+import static org.assertj.core.api.Assertions.*;
 
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ImportResource;
@@ -74,11 +75,11 @@ public class DynamicIndexEntityTests {
 
 		indexNameProvider.setIndexName("index1");
 		repository.save(new DynamicIndexEntity());
-		assertTrue(indexNameProvider.callsCount > initialCallsCount);
-		assertEquals(1L, repository.count());
+		assertThat(indexNameProvider.callsCount > initialCallsCount).isTrue();
+		assertThat(repository.count()).isEqualTo(1L);
 
 		indexNameProvider.setIndexName("index2");
-		assertEquals(0L, repository.count());
+		assertThat(repository.count()).isEqualTo(0L);
 	}
 
 	@ImportResource(value = "classpath:/dynamic-index-repository-test.xml")
diff --git a/src/test/java/org/springframework/data/elasticsearch/repository/config/ReactiveElasticsearchRepositoryConfigurationExtensionUnitTests.java b/src/test/java/org/springframework/data/elasticsearch/repository/config/ReactiveElasticsearchRepositoryConfigurationExtensionUnitTests.java
index 3724e954a..9739f20b0 100644
--- a/src/test/java/org/springframework/data/elasticsearch/repository/config/ReactiveElasticsearchRepositoryConfigurationExtensionUnitTests.java
+++ b/src/test/java/org/springframework/data/elasticsearch/repository/config/ReactiveElasticsearchRepositoryConfigurationExtensionUnitTests.java
@@ -15,11 +15,12 @@
  */
 package org.springframework.data.elasticsearch.repository.config;
 
-import static org.junit.Assert.*;
+import static org.assertj.core.api.Assertions.*;
 
 import java.util.Collection;
 
 import org.junit.Test;
+
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.core.env.Environment;