diff --git a/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java b/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java
index a5e478c7736aaf083af417671a7aab4d2d38db9f..630461802ead7b62f87804eebb45e9a109bb8888 100644
--- a/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java
+++ b/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java
@@ -175,6 +175,20 @@ public class CodeTester {
      */
     public String getLLastCall() { return llastCall; }
 
+    /**
+     * Default constructor
+     */
+    public CodeTester() { }
+
+    /**
+     * Constructor with timeout convenience
+     *
+     * @param timeout timeout in seconds
+     */
+    public CodeTester(int timeout) {
+        setTimeout(timeout);
+    }
+
     /**
      * Convenience method for throwing a FailedTestException with a
      * message constructed with expand.
@@ -1075,7 +1089,8 @@ public class CodeTester {
             return Utils.runWithTimeout(getTimeout(),
                                         () -> {
                 try {
-                    return m.invoke(tis, params);
+                    Object o = m.invoke(tis, params);
+                    return o;
                 } catch (Exception e) {
                     // this will end up at ExecutionException below,
                     // sometimes...
diff --git a/src/main/java/uk/ac/rhul/cs/javatester/Utils.java b/src/main/java/uk/ac/rhul/cs/javatester/Utils.java
index 7e1c22af0f2433536ef695d031eebc0dab1882ae..1389a4c230812d803fcb42cd92f33837c384bf53 100644
--- a/src/main/java/uk/ac/rhul/cs/javatester/Utils.java
+++ b/src/main/java/uk/ac/rhul/cs/javatester/Utils.java
@@ -19,6 +19,11 @@ public class Utils {
     /**
      * Run the function with a timeout and return the result.
      *
+     * TODO: this cannot stop infinite loops in student code as
+     * Java refuses to kill threads. Really needs to use a
+     * separate process. Or call System.exit at the end of your program
+     * (not nice).
+     *
      * @param seconds the timeout in seconds, or 0 or less if no timeout
      * @param f the function to call
      * @return the return value of the function