diff --git a/express-json/build.gradle b/express-json/build.gradle
index 21fd045..efe214e 100644
--- a/express-json/build.gradle
+++ b/express-json/build.gradle
@@ -10,8 +10,8 @@ configurations {
 apply from: '../publish.gradle'
 
 dependencies {
-    compile 'org.dmfs:jems:1.16'
-    compile 'org.dmfs:jems-testing:1.16'
+    implementation 'org.dmfs:jems2:2.2.0'
 
-    testCompile group: 'junit', name: 'junit', version: '4.12'
+    testImplementation 'org.dmfs:jems2-testing:2.2.0'
+    testImplementation 'junit:junit:4.12'
 }
diff --git a/express-json/src/main/java/org/dmfs/express/json/decorators/Nullable.java b/express-json/src/main/java/org/dmfs/express/json/decorators/Nullable.java
index a4d6244..bb9d74c 100644
--- a/express-json/src/main/java/org/dmfs/express/json/decorators/Nullable.java
+++ b/express-json/src/main/java/org/dmfs/express/json/decorators/Nullable.java
@@ -6,11 +6,11 @@
 import org.dmfs.express.json.elementary.Null;
 import org.dmfs.express.json.elementary.Number;
 import org.dmfs.express.json.elementary.String;
-import org.dmfs.jems.optional.decorators.Mapped;
-import org.dmfs.jems.single.Single;
-import org.dmfs.jems.single.combined.Backed;
-import org.dmfs.optional.NullSafe;
-import org.dmfs.optional.Optional;
+import org.dmfs.jems2.Optional;
+import org.dmfs.jems2.Single;
+import org.dmfs.jems2.optional.Mapped;
+import org.dmfs.jems2.optional.NullSafe;
+import org.dmfs.jems2.single.Backed;
 
 import java.io.IOException;
 
diff --git a/express-json/src/main/java/org/dmfs/express/json/elementary/Array.java b/express-json/src/main/java/org/dmfs/express/json/elementary/Array.java
index 129c256..42eb06f 100644
--- a/express-json/src/main/java/org/dmfs/express/json/elementary/Array.java
+++ b/express-json/src/main/java/org/dmfs/express/json/elementary/Array.java
@@ -4,8 +4,8 @@
 import org.dmfs.express.json.JsonValue;
 import org.dmfs.express.json.Jsonable;
 import org.dmfs.express.json.adapters.Json;
-import org.dmfs.iterables.elementary.Seq;
-import org.dmfs.jems.iterable.decorators.Mapped;
+import org.dmfs.jems2.iterable.Mapped;
+import org.dmfs.jems2.iterable.Seq;
 
 import java.io.IOException;
 
@@ -24,7 +24,7 @@ public final class Array implements JsonValue
      * Creates a {@link JsonValue} array of {@link Jsonable}s.
      *
      * @param elements
-     *         the elements of the Array
+     *     the elements of the Array
      */
     public Array(Jsonable... elements)
     {
@@ -36,7 +36,7 @@ public Array(Jsonable... elements)
      * Creates a {@link JsonValue} array of {@link Boolean}s.
      *
      * @param elements
-     *         the elements of the Array
+     *     the elements of the Array
      */
     public Array(java.lang.Boolean... elements)
     {
@@ -48,7 +48,7 @@ public Array(java.lang.Boolean... elements)
      * Creates a {@link JsonValue} array of {@link Number}s.
      *
      * @param elements
-     *         the elements of the Array
+     *     the elements of the Array
      */
     public Array(java.lang.Number... elements)
     {
@@ -60,7 +60,7 @@ public Array(java.lang.Number... elements)
      * Creates a {@link JsonValue} array of {@link CharSequence}s.
      *
      * @param elements
-     *         the elements of the Array
+     *     the elements of the Array
      */
     public Array(CharSequence... elements)
     {
@@ -72,7 +72,7 @@ public Array(CharSequence... elements)
      * Creates a {@link JsonValue} array of arbitrary {@link JsonValue} values.
      *
      * @param elements
-     *         the elements of the Array
+     *     the elements of the Array
      */
     public Array(JsonValue... elements)
     {
@@ -84,7 +84,7 @@ public Array(JsonValue... elements)
      * Creates a {@link JsonValue} array of arbitrary {@link JsonValue} values.
      *
      * @param elements
-     *         An {@link Iterable} of {@link JsonValue} values.
+     *     An {@link Iterable} of {@link JsonValue} values.
      */
     public Array(Iterable<JsonValue> elements)
     {
diff --git a/express-json/src/main/java/org/dmfs/express/json/elementary/JsonText.java b/express-json/src/main/java/org/dmfs/express/json/elementary/JsonText.java
index b580acf..afe3a62 100644
--- a/express-json/src/main/java/org/dmfs/express/json/elementary/JsonText.java
+++ b/express-json/src/main/java/org/dmfs/express/json/elementary/JsonText.java
@@ -2,7 +2,7 @@
 
 import org.dmfs.express.json.JsonValue;
 import org.dmfs.express.json.sinks.StringBuilderSink;
-import org.dmfs.jems.single.Single;
+import org.dmfs.jems2.Single;
 
 import java.io.IOException;
 import java.lang.String;
diff --git a/express-json/src/main/java/org/dmfs/express/json/elementary/Member.java b/express-json/src/main/java/org/dmfs/express/json/elementary/Member.java
index 39ca8fa..ceca7eb 100644
--- a/express-json/src/main/java/org/dmfs/express/json/elementary/Member.java
+++ b/express-json/src/main/java/org/dmfs/express/json/elementary/Member.java
@@ -3,7 +3,7 @@
 import org.dmfs.express.json.JsonValue;
 import org.dmfs.express.json.Jsonable;
 import org.dmfs.express.json.adapters.Json;
-import org.dmfs.jems.pair.Pair;
+import org.dmfs.jems2.Pair;
 
 import java.lang.Object;
 
diff --git a/express-json/src/main/java/org/dmfs/express/json/elementary/Object.java b/express-json/src/main/java/org/dmfs/express/json/elementary/Object.java
index 86ced9e..3bb6ab0 100644
--- a/express-json/src/main/java/org/dmfs/express/json/elementary/Object.java
+++ b/express-json/src/main/java/org/dmfs/express/json/elementary/Object.java
@@ -3,8 +3,8 @@
 import org.dmfs.express.json.JsonSink;
 import org.dmfs.express.json.JsonValue;
 import org.dmfs.express.json.decorators.Nullable;
-import org.dmfs.iterables.elementary.Seq;
-import org.dmfs.jems.pair.Pair;
+import org.dmfs.jems2.Pair;
+import org.dmfs.jems2.iterable.Seq;
 
 import java.io.IOException;
 
diff --git a/express-json/src/main/java/org/dmfs/express/json/elementary/String.java b/express-json/src/main/java/org/dmfs/express/json/elementary/String.java
index ca79ffa..7089767 100644
--- a/express-json/src/main/java/org/dmfs/express/json/elementary/String.java
+++ b/express-json/src/main/java/org/dmfs/express/json/elementary/String.java
@@ -2,7 +2,7 @@
 
 import org.dmfs.express.json.JsonSink;
 import org.dmfs.express.json.JsonValue;
-import org.dmfs.jems.charsequence.elementary.Hex;
+import org.dmfs.jems2.charsequence.Hex;
 
 import java.io.IOException;
 
diff --git a/express-json/src/test/java/org/dmfs/express/json/elementary/ArrayTest.java b/express-json/src/test/java/org/dmfs/express/json/elementary/ArrayTest.java
index be991c8..cc22cb4 100644
--- a/express-json/src/test/java/org/dmfs/express/json/elementary/ArrayTest.java
+++ b/express-json/src/test/java/org/dmfs/express/json/elementary/ArrayTest.java
@@ -2,8 +2,8 @@
 
 import org.dmfs.express.json.JsonValue;
 import org.dmfs.express.json.Jsonable;
-import org.dmfs.iterables.EmptyIterable;
-import org.dmfs.iterables.elementary.Seq;
+import org.dmfs.jems2.iterable.EmptyIterable;
+import org.dmfs.jems2.iterable.Seq;
 import org.junit.Test;
 
 import static org.dmfs.express.json.hamcrest.JsonSerializationMatcher.serializesTo;
diff --git a/express-json/src/test/java/org/dmfs/express/json/elementary/JsonTextTest.java b/express-json/src/test/java/org/dmfs/express/json/elementary/JsonTextTest.java
index b9f7df8..f91e106 100644
--- a/express-json/src/test/java/org/dmfs/express/json/elementary/JsonTextTest.java
+++ b/express-json/src/test/java/org/dmfs/express/json/elementary/JsonTextTest.java
@@ -4,7 +4,7 @@
 
 import java.io.IOException;
 
-import static org.dmfs.jems.hamcrest.matchers.SingleMatcher.hasValue;
+import static org.dmfs.jems2.hamcrest.matchers.single.SingleMatcher.hasValue;
 import static org.junit.Assert.assertThat;
 
 
diff --git a/express-json/src/test/java/org/dmfs/express/json/elementary/MemberTest.java b/express-json/src/test/java/org/dmfs/express/json/elementary/MemberTest.java
index 390d6db..0c8fb58 100644
--- a/express-json/src/test/java/org/dmfs/express/json/elementary/MemberTest.java
+++ b/express-json/src/test/java/org/dmfs/express/json/elementary/MemberTest.java
@@ -4,7 +4,7 @@
 import org.junit.Test;
 
 import static org.dmfs.express.json.hamcrest.JsonSerializationMatcher.serializesTo;
-import static org.dmfs.jems.hamcrest.matchers.PairMatcher.pair;
+import static org.dmfs.jems2.hamcrest.matchers.pair.PairMatcher.pair;
 import static org.junit.Assert.assertThat;
 
 
@@ -25,5 +25,4 @@ public void test() throws Exception
         assertThat(new Member("abc", new String("123")), pair(serializesTo("\"abc\""), serializesTo("\"123\"")));
         assertThat(new Member(new String("abc"), new String("123")), pair(serializesTo("\"abc\""), serializesTo("\"123\"")));
     }
-
 }
\ No newline at end of file
diff --git a/express-json/src/test/java/org/dmfs/express/json/elementary/ObjectTest.java b/express-json/src/test/java/org/dmfs/express/json/elementary/ObjectTest.java
index a06bf11..d1178c9 100644
--- a/express-json/src/test/java/org/dmfs/express/json/elementary/ObjectTest.java
+++ b/express-json/src/test/java/org/dmfs/express/json/elementary/ObjectTest.java
@@ -19,7 +19,7 @@ public void test() throws Exception
         assertThat(new Object(new Member("a", 1), new Member("x", "y")), serializesTo("{\"a\":1,\"x\":\"y\"}"));
         assertThat(new Object(new Member("a", new Object()), new Member("x", "y")), serializesTo("{\"a\":{},\"x\":\"y\"}"));
         assertThat(new Object(new Member("a", new Object(new Member("b", "q"))), new Member("x", new Array(1, 2, 3))),
-                serializesTo("{\"a\":{\"b\":\"q\"},\"x\":[1,2,3]}"));
+            serializesTo("{\"a\":{\"b\":\"q\"},\"x\":[1,2,3]}"));
     }
 
 }
\ No newline at end of file
diff --git a/express-json/src/main/java/org/dmfs/express/json/hamcrest/JsonSerializationMatcher.java b/express-json/src/test/java/org/dmfs/express/json/hamcrest/JsonSerializationMatcher.java
similarity index 100%
rename from express-json/src/main/java/org/dmfs/express/json/hamcrest/JsonSerializationMatcher.java
rename to express-json/src/test/java/org/dmfs/express/json/hamcrest/JsonSerializationMatcher.java
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index a0488c1..bdb63e6 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.5-rc-2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip