diff --git a/kotlin/tests/pom.xml b/kotlin/tests/pom.xml
index 4c9c541..fef7548 100644
--- a/kotlin/tests/pom.xml
+++ b/kotlin/tests/pom.xml
@@ -108,7 +108,7 @@
               <sourceDirs>
                 <sourceDir>src/test/kotlin</sourceDir>
                 <sourceDir>src/test/java</sourceDir>
-                <sourceDir>target/generated-sources/kapt/test</sourceDir>
+                <sourceDir>target/generated-sources/kaptKotlin/test</sourceDir>
               </sourceDirs>
             </configuration>
           </execution>
@@ -144,7 +144,9 @@
           <execution>
             <id>java-test-compile</id>
             <phase>test-compile</phase>
-            <goals> <goal>testCompile</goal> </goals>
+            <goals>
+              <goal>testCompile</goal>
+            </goals>
           </execution>
         </executions>
       </plugin>
diff --git a/moshi/src/test/java/com/squareup/moshi/JsonValueWriterTest.java b/moshi/src/test/java/com/squareup/moshi/JsonValueWriterTest.java
index a321104..7faae6f 100644
--- a/moshi/src/test/java/com/squareup/moshi/JsonValueWriterTest.java
+++ b/moshi/src/test/java/com/squareup/moshi/JsonValueWriterTest.java
@@ -18,6 +18,7 @@ package com.squareup.moshi;
 import java.io.IOException;
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -28,7 +29,6 @@ import org.junit.Test;
 
 import static java.util.Collections.singletonList;
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.entry;
 import static org.junit.Assert.fail;
 
 public final class JsonValueWriterTest {
@@ -57,8 +57,11 @@ public final class JsonValueWriterTest {
     writer.name("d").nullValue();
     writer.endObject();
 
-    assertThat((Map<?, ?>) writer.root()).containsExactly(
-        entry("a", "s"), entry("b", 1.5d), entry("c", true), entry("d", null));
+    assertThat((Map<String, Object>) writer.root()).containsExactly(
+        new SimpleEntry<String, Object>("a", "s"),
+        new SimpleEntry<String, Object>("b", 1.5d),
+        new SimpleEntry<String, Object>("c", true),
+        new SimpleEntry<String, Object>("d", null));
   }
 
   @Test public void repeatedNameThrows() throws IOException {
@@ -253,8 +256,11 @@ public final class JsonValueWriterTest {
     writer.name("d");
     writer.value(new Buffer().writeUtf8("null"));
     writer.endObject();
-    assertThat((Map<?, ?>) writer.root()).containsExactly(
-      entry("a", singletonList("value")), entry("b", 2.0d), entry("c", 3L), entry("d", null));
+    assertThat((Map<String, Object>) writer.root()).containsExactly(
+        new SimpleEntry<String, Object>("a", singletonList("value")),
+        new SimpleEntry<String, Object>("b", 2.0d),
+        new SimpleEntry<String, Object>("c", 3L),
+        new SimpleEntry<String, Object>("d", null));
   }
 
   /**
diff --git a/moshi/src/test/java/com/squareup/moshi/MapJsonAdapterTest.java b/moshi/src/test/java/com/squareup/moshi/MapJsonAdapterTest.java
index c967047..d368ce6 100644
--- a/moshi/src/test/java/com/squareup/moshi/MapJsonAdapterTest.java
+++ b/moshi/src/test/java/com/squareup/moshi/MapJsonAdapterTest.java
@@ -17,12 +17,12 @@ package com.squareup.moshi;
 
 import java.io.IOException;
 import java.lang.reflect.Type;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import okio.Buffer;
-import org.assertj.core.data.MapEntry;
 import org.junit.Test;
 
 import static com.squareup.moshi.TestUtil.newReader;
@@ -45,7 +45,9 @@ public final class MapJsonAdapterTest {
     Map<String, Boolean> fromJson = fromJson(
         String.class, Boolean.class, "{\"a\":true,\"b\":false,\"c\":null}");
     assertThat(fromJson).containsExactly(
-        MapEntry.entry("a", true), MapEntry.entry("b", false), MapEntry.entry("c", null));
+        new SimpleEntry<String, Boolean>("a", true),
+        new SimpleEntry<String, Boolean>("b", false),
+        new SimpleEntry<String, Boolean>("c", null));
   }
 
   @Test public void mapWithNullKeyFailsToEmit() throws Exception {
@@ -119,13 +121,15 @@ public final class MapJsonAdapterTest {
     String toJson = toJson(Integer.class, Boolean.class, map);
     assertThat(toJson).isEqualTo("{\"5\":true,\"6\":false,\"7\":null}");
 
-    Map<String, Boolean> fromJson = fromJson(
+    Map<Integer, Boolean> fromJson = fromJson(
         Integer.class, Boolean.class, "{\"5\":true,\"6\":false,\"7\":null}");
     assertThat(fromJson).containsExactly(
-        MapEntry.entry(5, true), MapEntry.entry(6, false), MapEntry.entry(7, null));
+        new SimpleEntry<Integer, Boolean>(5, true),
+        new SimpleEntry<Integer, Boolean>(6, false),
+        new SimpleEntry<Integer, Boolean>(7, null));
   }
 
-  @Test public void mapWithNonStringKeysToJsonObject() throws Exception {
+  @Test public void mapWithNonStringKeysToJsonObject() {
     Map<Integer, Boolean> map = new LinkedHashMap<>();
     map.put(5, true);
     map.put(6, false);
diff --git a/moshi/src/test/java/com/squareup/moshi/ObjectAdapterTest.java b/moshi/src/test/java/com/squareup/moshi/ObjectAdapterTest.java
index a844d94..72d2347 100644
--- a/moshi/src/test/java/com/squareup/moshi/ObjectAdapterTest.java
+++ b/moshi/src/test/java/com/squareup/moshi/ObjectAdapterTest.java
@@ -22,6 +22,7 @@ import java.math.BigDecimal;
 import java.util.AbstractCollection;
 import java.util.AbstractList;
 import java.util.AbstractMap;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.AbstractSet;
 import java.util.Arrays;
 import java.util.Collection;
@@ -40,10 +41,9 @@ import org.junit.Test;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.entry;
 
 public final class ObjectAdapterTest {
-  @Test public void toJsonUsesRuntimeType() throws Exception {
+  @Test public void toJsonUsesRuntimeType() {
     Delivery delivery = new Delivery();
     delivery.address = "1455 Market St.";
     Pizza pizza = new Pizza();
@@ -62,7 +62,7 @@ public final class ObjectAdapterTest {
         + "}");
   }
 
-  @Test public void toJsonJavaLangObject() throws Exception {
+  @Test public void toJsonJavaLangObject() {
     Moshi moshi = new Moshi.Builder().build();
     JsonAdapter<Object> adapter = moshi.adapter(Object.class);
     assertThat(adapter.toJson(new Object())).isEqualTo("{}");
@@ -104,7 +104,7 @@ public final class ObjectAdapterTest {
         .isEqualTo(emptyDelivery);
   }
 
-  @Test public void toJsonCoercesRuntimeTypeForCollections() throws Exception {
+  @Test public void toJsonCoercesRuntimeTypeForCollections() {
     Collection<String> collection = new AbstractCollection<String>() {
       @Override public Iterator<String> iterator() {
         return Collections.singleton("A").iterator();
@@ -119,7 +119,7 @@ public final class ObjectAdapterTest {
     assertThat(adapter.toJson(collection)).isEqualTo("[\"A\"]");
   }
 
-  @Test public void toJsonCoercesRuntimeTypeForLists() throws Exception {
+  @Test public void toJsonCoercesRuntimeTypeForLists() {
     List<String> list = new AbstractList<String>() {
       @Override public String get(int i) {
         return "A";
@@ -135,7 +135,7 @@ public final class ObjectAdapterTest {
     assertThat(adapter.toJson(list)).isEqualTo("[\"A\"]");
   }
 
-  @Test public void toJsonCoercesRuntimeTypeForSets() throws Exception {
+  @Test public void toJsonCoercesRuntimeTypeForSets() {
     Set<String> set = new AbstractSet<String>() {
       @Override public Iterator<String> iterator() {
         return Collections.singleton("A").iterator();
@@ -151,7 +151,7 @@ public final class ObjectAdapterTest {
   }
 
   @Ignore // We don't support raw maps, like Map<Object, Object>. (Even if the keys are strings!)
-  @Test public void toJsonCoercesRuntimeTypeForMaps() throws Exception {
+  @Test public void toJsonCoercesRuntimeTypeForMaps() {
     Map<String, Boolean> map = new AbstractMap<String, Boolean>() {
       @Override public Set<Entry<String, Boolean>> entrySet() {
         return Collections.singletonMap("A", true).entrySet();
@@ -163,7 +163,7 @@ public final class ObjectAdapterTest {
     assertThat(adapter.toJson(map)).isEqualTo("{\"A\":true}");
   }
 
-  @Test public void toJsonUsesTypeAdapters() throws Exception {
+  @Test public void toJsonUsesTypeAdapters() {
     Object dateAdapter = new Object() {
       @ToJson Long dateToJson(Date d) {
         return d.getTime();
@@ -185,7 +185,7 @@ public final class ObjectAdapterTest {
    */
   @Test public void objectAdapterDelegatesStringNamesAndValues() throws Exception {
     JsonAdapter<String> stringAdapter = new JsonAdapter<String>() {
-      @Nullable @Override public String fromJson(JsonReader reader) throws IOException {
+      @Override public String fromJson(JsonReader reader) throws IOException {
         return reader.nextString().toUpperCase(Locale.US);
       }
 
@@ -198,8 +198,9 @@ public final class ObjectAdapterTest {
         .add(String.class, stringAdapter)
         .build();
     JsonAdapter<Object> objectAdapter = moshi.adapter(Object.class);
-    Map<?, ?> value = (Map<?, ?>) objectAdapter.fromJson("{\"a\":\"b\", \"c\":\"d\"}");
-    assertThat(value).containsExactly(entry("A", "B"), entry("C", "D"));
+    Map<String, String> value
+        = (Map<String, String>) objectAdapter.fromJson("{\"a\":\"b\", \"c\":\"d\"}");
+    assertThat(value).containsExactly(new SimpleEntry<>("A", "B"), new SimpleEntry<>("C", "D"));
   }
 
   /**
@@ -241,7 +242,7 @@ public final class ObjectAdapterTest {
   /** Confirm that the built-in adapter for Object delegates to user-supplied adapters for lists. */
   @Test public void objectAdapterDelegatesLists() throws Exception {
     JsonAdapter<List<?>> listAdapter = new JsonAdapter<List<?>>() {
-      @Override public @Nullable List<?> fromJson(JsonReader reader) throws IOException {
+      @Override public List<?> fromJson(JsonReader reader) throws IOException {
         reader.skipValue();
         return singletonList("z");
       }
@@ -262,7 +263,7 @@ public final class ObjectAdapterTest {
   /** Confirm that the built-in adapter for Object delegates to user-supplied adapters for maps. */
   @Test public void objectAdapterDelegatesMaps() throws Exception {
     JsonAdapter<Map<?, ?>> mapAdapter = new JsonAdapter<Map<?, ?>>() {
-      @Override public @Nullable Map<?, ?> fromJson(JsonReader reader) throws IOException {
+      @Override public Map<?, ?> fromJson(JsonReader reader) throws IOException {
         reader.skipValue();
         return singletonMap("x", "y");
       }
diff --git a/pom.xml b/pom.xml
index db6ad7b..54d5fb8 100644
--- a/pom.xml
+++ b/pom.xml
@@ -29,8 +29,8 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <java.version>1.7</java.version>
-    <kotlin.version>1.2.21</kotlin.version>
-    <kotlin-metadata.version>1.3.0</kotlin-metadata.version>
+    <kotlin.version>1.2.71</kotlin.version>
+    <kotlin-metadata.version>1.4.0</kotlin-metadata.version>
     <dokka.version>0.9.17</dokka.version>
     <maven-assembly.version>3.1.0</maven-assembly.version>
 
@@ -38,9 +38,9 @@
     <okio.version>1.15.0</okio.version>
 
     <!-- Test Dependencies -->
-    <compile-testing.version>0.8</compile-testing.version>
+    <compile-testing.version>0.15</compile-testing.version>
     <junit.version>4.12</junit.version>
-    <assertj.version>1.7.0</assertj.version>
+    <assertj.version>3.11.1</assertj.version>
   </properties>
 
   <scm>