diff --git a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/CreatePortfolioCommand.java b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/CreatePortfolioCommand.java
deleted file mode 100644
index 8c05854..0000000
--- a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/CreatePortfolioCommand.java
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (c) 2010-2012. Axon Framework
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.axonframework.samples.trader.api.portfolio;
-
-import org.axonframework.samples.trader.api.orders.trades.PortfolioId;
-import org.axonframework.samples.trader.api.users.UserId;
-
-/**
- * @author Jettro Coenradie
- */
-public class CreatePortfolioCommand {
-
-    private PortfolioId portfolioId;
-    private UserId userId;
-
-    public CreatePortfolioCommand(PortfolioId portfolioId, UserId userId) {
-        this.portfolioId = portfolioId;
-        this.userId = userId;
-    }
-
-    public UserId getUserId() {
-        return userId;
-    }
-
-    public PortfolioId getPortfolioId() {
-        return portfolioId;
-    }
-}
diff --git a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/PortfolioCreatedEvent.java b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/PortfolioCreatedEvent.java
deleted file mode 100644
index 699a620..0000000
--- a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/PortfolioCreatedEvent.java
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (c) 2010-2012. Axon Framework
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.axonframework.samples.trader.api.portfolio;
-
-import org.axonframework.samples.trader.api.orders.trades.PortfolioId;
-import org.axonframework.samples.trader.api.users.UserId;
-
-/**
- * @author Jettro Coenradie
- */
-public class PortfolioCreatedEvent {
-
-    private PortfolioId portfolioId;
-    private UserId userId;
-
-    public PortfolioCreatedEvent(PortfolioId portfolioId, UserId userId) {
-        this.portfolioId = portfolioId;
-        this.userId = userId;
-    }
-
-    public UserId getUserId() {
-        return this.userId;
-    }
-
-    public PortfolioId getPortfolioId() {
-        return this.portfolioId;
-    }
-}
diff --git a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/commands.kt b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/commands.kt
index 8b8e43b..0e28b13 100644
--- a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/commands.kt
+++ b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/commands.kt
@@ -1,12 +1,10 @@
 package org.axonframework.samples.trader.api.portfolio.cash
 
-import org.axonframework.commandhandling.TargetAggregateIdentifier
 import org.axonframework.samples.trader.api.orders.transaction.TransactionId
+import org.axonframework.samples.trader.api.portfolio.PortfolioCommand
 import org.axonframework.samples.trader.api.portfolio.PortfolioId
 import javax.validation.constraints.Min
 
-abstract class PortfolioCommand(@TargetAggregateIdentifier open val portfolioId: PortfolioId)
-
 data class CancelCashReservationCommand(
         override val portfolioId: PortfolioId,
         val transactionId: TransactionId,
diff --git a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/events.kt b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/events.kt
index cdfdd88..5f52747 100644
--- a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/events.kt
+++ b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/cash/events.kt
@@ -1,9 +1,8 @@
 package org.axonframework.samples.trader.api.portfolio.cash
 
-import org.axonframework.samples.trader.api.orders.trades.PortfolioId
 import org.axonframework.samples.trader.api.orders.transaction.TransactionId
-
-abstract class PortfolioEvent(open val portfolioId: PortfolioId)
+import org.axonframework.samples.trader.api.portfolio.PortfolioEvent
+import org.axonframework.samples.trader.api.portfolio.PortfolioId
 
 data class CashDepositedEvent(
         override val portfolioId: PortfolioId,
diff --git a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/commands.kt b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/commands.kt
new file mode 100644
index 0000000..66097a5
--- /dev/null
+++ b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/commands.kt
@@ -0,0 +1,11 @@
+package org.axonframework.samples.trader.api.portfolio
+
+import org.axonframework.commandhandling.TargetAggregateIdentifier
+import org.axonframework.samples.trader.api.users.UserId
+
+abstract class PortfolioCommand(@TargetAggregateIdentifier open val portfolioId: PortfolioId)
+
+data class CreatePortfolioCommand(
+        override val portfolioId: PortfolioId,
+        val userId: UserId
+) : PortfolioCommand(portfolioId)
diff --git a/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/events.kt b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/events.kt
new file mode 100644
index 0000000..64285e3
--- /dev/null
+++ b/core-api/src/main/java/org/axonframework/samples/trader/api/portfolio/events.kt
@@ -0,0 +1,10 @@
+package org.axonframework.samples.trader.api.portfolio
+
+import org.axonframework.samples.trader.api.users.UserId
+
+abstract class PortfolioEvent(open val portfolioId: PortfolioId)
+
+class PortfolioCreatedEvent(
+        override val portfolioId: PortfolioId,
+        val userId: UserId
+) : PortfolioEvent(portfolioId)