diff --git a/.idea/misc.xml b/.idea/misc.xml
index 85b2911..7fc513e 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="EntryPointsManager">
+    <list size="1">
+      <item index="0" class="java.lang.String" itemvalue="function.FunctionNames" />
+    </list>
+  </component>
   <component name="MavenProjectsManager">
     <option name="originalFiles">
       <list>
diff --git a/src/main/kotlin/function/builtin/FUSE.java b/src/main/kotlin/function/builtin/FUSE.java
deleted file mode 100644
index c662551..0000000
--- a/src/main/kotlin/function/builtin/FUSE.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package function.builtin;
-
-import function.ArgumentValidator;
-import function.FunctionNames;
-import function.LispFunction;
-import sexpression.Atom;
-import sexpression.Cons;
-import sexpression.LispString;
-import sexpression.SExpression;
-import sexpression.Symbol;
-
-@FunctionNames({ "FUSE" })
-public class FUSE extends LispFunction {
-
-    private static final String SEPARATOR = "-";
-
-    private ArgumentValidator argumentValidator;
-
-    public FUSE(String name) {
-        this.argumentValidator = new ArgumentValidator(name);
-        this.argumentValidator.setExactNumberOfArguments(2);
-        this.argumentValidator.setFirstArgumentExpectedType(Symbol.class);
-        this.argumentValidator.setTrailingArgumentExpectedType(Atom.class);
-        this.argumentValidator.setTrailingArgumentExcludedType(LispString.class);
-    }
-
-    @Override
-    public SExpression call(Cons argumentList) {
-        argumentValidator.validate(argumentList);
-        Symbol left = (Symbol) argumentList.getFirst();
-        Atom right = (Atom) ((Cons) argumentList.getRest()).getFirst();
-
-        return new Symbol(left.toString() + SEPARATOR + right.toString());
-    }
-}
diff --git a/src/main/kotlin/function/builtin/Fuse.kt b/src/main/kotlin/function/builtin/Fuse.kt
new file mode 100644
index 0000000..31534a7
--- /dev/null
+++ b/src/main/kotlin/function/builtin/Fuse.kt
@@ -0,0 +1,34 @@
+package function.builtin
+
+import function.ArgumentValidator
+import function.FunctionNames
+import function.LispFunction
+import sexpression.Atom
+import sexpression.Cons
+import sexpression.LispString
+import sexpression.SExpression
+import sexpression.Symbol
+
+@FunctionNames("FUSE")
+class Fuse(name: String) : LispFunction() {
+
+    private val argumentValidator: ArgumentValidator = ArgumentValidator(name).apply {
+        setExactNumberOfArguments(2)
+        setFirstArgumentExpectedType(Symbol::class.java)
+        setTrailingArgumentExpectedType(Atom::class.java)
+        setTrailingArgumentExcludedType(LispString::class.java)
+    }
+
+    override fun call(argumentList: Cons): SExpression {
+        argumentValidator.validate(argumentList)
+
+        val left = argumentList.first as Symbol
+        val right = (argumentList.rest as Cons).first as Atom
+
+        return Symbol("$left$SEPARATOR$right")
+    }
+
+    companion object {
+        private const val SEPARATOR = "-"
+    }
+}
diff --git a/src/test/kotlin/function/builtin/special/FUSETest.java b/src/test/kotlin/function/builtin/FuseTest.java
similarity index 94%
rename from src/test/kotlin/function/builtin/special/FUSETest.java
rename to src/test/kotlin/function/builtin/FuseTest.java
index ddd9586..1728c6c 100644
--- a/src/test/kotlin/function/builtin/special/FUSETest.java
+++ b/src/test/kotlin/function/builtin/FuseTest.java
@@ -1,4 +1,4 @@
-package function.builtin.special;
+package function.builtin;
 
 import function.ArgumentValidator.BadArgumentTypeException;
 import function.ArgumentValidator.TooFewArgumentsException;
@@ -10,7 +10,7 @@ import testutil.SymbolAndFunctionCleaner;
 import static testutil.TestUtilities.assertSExpressionsMatch;
 import static testutil.TestUtilities.evaluateString;
 
-public class FUSETest extends SymbolAndFunctionCleaner {
+public class FuseTest extends SymbolAndFunctionCleaner {
 
     @Test
     public void fuseSymbolAndNumber() {