diff --git a/ultrasonic/src/main/java/org/moire/ultrasonic/util/TimeLimitedCache.java b/ultrasonic/src/main/java/org/moire/ultrasonic/util/TimeLimitedCache.java
deleted file mode 100644
index 1a39a440..00000000
--- a/ultrasonic/src/main/java/org/moire/ultrasonic/util/TimeLimitedCache.java
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- This file is part of Subsonic.
-
- Subsonic 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.
-
- Subsonic 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 Subsonic.  If not, see <http://www.gnu.org/licenses/>.
-
- Copyright 2009 (C) Sindre Mehus
- */
-package org.moire.ultrasonic.util;
-
-import java.lang.ref.SoftReference;
-import java.util.concurrent.TimeUnit;
-
-/**
- * @author Sindre Mehus
- * @version $Id$
- */
-public class TimeLimitedCache<T>
-{
-
-	private SoftReference<T> value;
-	private final long ttlMillis;
-	private long expires;
-
-	public TimeLimitedCache(long ttl, TimeUnit timeUnit)
-	{
-		this.ttlMillis = TimeUnit.MILLISECONDS.convert(ttl, timeUnit);
-	}
-
-	public T get()
-	{
-		return System.currentTimeMillis() < expires ? value.get() : null;
-	}
-
-	public void set(T value)
-	{
-		set(value, ttlMillis, TimeUnit.MILLISECONDS);
-	}
-
-	public void set(T value, long ttl, TimeUnit timeUnit)
-	{
-		this.value = new SoftReference<T>(value);
-		expires = System.currentTimeMillis() + timeUnit.toMillis(ttl);
-	}
-
-	public void clear()
-	{
-		expires = 0L;
-		value = null;
-	}
-}
diff --git a/ultrasonic/src/main/java/org/moire/ultrasonic/util/TimeLimitedCache.kt b/ultrasonic/src/main/java/org/moire/ultrasonic/util/TimeLimitedCache.kt
new file mode 100644
index 00000000..09afdb41
--- /dev/null
+++ b/ultrasonic/src/main/java/org/moire/ultrasonic/util/TimeLimitedCache.kt
@@ -0,0 +1,31 @@
+/*
+ * TimeLimitedCache.kt
+ * Copyright (C) 2009-2021 Ultrasonic developers
+ *
+ * Distributed under terms of the GNU GPLv3 license.
+ */
+package org.moire.ultrasonic.util
+
+import java.lang.ref.SoftReference
+import java.util.concurrent.TimeUnit
+
+class TimeLimitedCache<T>(expiresAfter: Long = 60L, timeUnit: TimeUnit = TimeUnit.MINUTES) {
+    private var value: SoftReference<T>? = null
+    private val expiresMillis: Long = TimeUnit.MILLISECONDS.convert(expiresAfter, timeUnit)
+    private var expires: Long = 0
+
+    fun get(): T? {
+        return if (System.currentTimeMillis() < expires) value!!.get() else null
+    }
+
+    @JvmOverloads
+    fun set(value: T, ttl: Long = expiresMillis, timeUnit: TimeUnit = TimeUnit.MILLISECONDS) {
+        this.value = SoftReference(value)
+        expires = System.currentTimeMillis() + timeUnit.toMillis(ttl)
+    }
+
+    fun clear() {
+        expires = 0L
+        value = null
+    }
+}