diff --git a/uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.java b/uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.java
deleted file mode 100644
index df952496c..000000000
--- a/uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright (C) 2016-2021 Álinson Santos Xavier <git@axavier.org>
- *
- * This file is part of Loop Habit Tracker.
- *
- * Loop Habit Tracker is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by the
- * Free Software Foundation, either version 3 of the License, or (at your
- * option) any later version.
- *
- * Loop Habit Tracker is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.isoron.uhabits.core.tasks;
-
-import java.util.*;
-
-public class SingleThreadTaskRunner implements TaskRunner
-{
-    private List<Listener> listeners = new LinkedList<>();
-
-    @Override
-    public void addListener(Listener listener)
-    {
-        listeners.add(listener);
-    }
-
-    @Override
-    public void execute(Task task)
-    {
-        for(Listener l : listeners) l.onTaskStarted(task);
-        if(!task.isCanceled())
-        {
-            task.onAttached(this);
-            task.onPreExecute();
-            task.doInBackground();
-            task.onPostExecute();
-        }
-        for(Listener l : listeners) l.onTaskFinished(task);
-    }
-
-    @Override
-    public int getActiveTaskCount()
-    {
-        return 0;
-    }
-
-    @Override
-    public void publishProgress(Task task, int progress)
-    {
-        task.onProgressUpdate(progress);
-    }
-
-    @Override
-    public void removeListener(Listener listener)
-    {
-        listeners.remove(listener);
-    }
-}
diff --git a/uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt b/uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt
new file mode 100644
index 000000000..c2a151a7b
--- /dev/null
+++ b/uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2016-2021 Álinson Santos Xavier <git@axavier.org>
+ *
+ * This file is part of Loop Habit Tracker.
+ *
+ * Loop Habit Tracker is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * Loop Habit Tracker is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.isoron.uhabits.core.tasks
+
+import java.util.LinkedList
+
+class SingleThreadTaskRunner : TaskRunner {
+    private val listeners: MutableList<TaskRunner.Listener> = LinkedList()
+    override fun addListener(listener: TaskRunner.Listener) {
+        listeners.add(listener)
+    }
+
+    override fun execute(task: Task) {
+        for (l in listeners) l.onTaskStarted(task)
+        if (!task.isCanceled) {
+            task.onAttached(this)
+            task.onPreExecute()
+            task.doInBackground()
+            task.onPostExecute()
+        }
+        for (l in listeners) l.onTaskFinished(task)
+    }
+
+    override fun getActiveTaskCount(): Int {
+        return 0
+    }
+
+    override fun publishProgress(task: Task, progress: Int) {
+        task.onProgressUpdate(progress)
+    }
+
+    override fun removeListener(listener: TaskRunner.Listener) {
+        listeners.remove(listener)
+    }
+}