diff --git a/tools/cooja/java/se/sics/cooja/plugins/ScriptRunnerNoGUI.java b/tools/cooja/java/se/sics/cooja/plugins/ScriptRunnerNoGUI.java
index bbf89aff5..4cfa2da41 100644
--- a/tools/cooja/java/se/sics/cooja/plugins/ScriptRunnerNoGUI.java
+++ b/tools/cooja/java/se/sics/cooja/plugins/ScriptRunnerNoGUI.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: ScriptRunnerNoGUI.java,v 1.2 2008/09/18 14:24:46 fros4943 Exp $
+ * $Id: ScriptRunnerNoGUI.java,v 1.3 2008/09/18 14:55:21 fros4943 Exp $
  */
 
 package se.sics.cooja.plugins;
@@ -122,6 +122,7 @@ public class ScriptRunnerNoGUI implements Plugin {
       /* Load simulation */
       final Simulation sim = gui.loadSimulationConfig(config, true);
       if (sim == null) {
+        System.exit(1);
         return false;
       }
       gui.setSimulation(sim);
@@ -171,11 +172,14 @@ public class ScriptRunnerNoGUI implements Plugin {
       sim.startSimulation();
     } catch (IOException e) {
       logger.fatal("Error when running script: " + e);
+      System.exit(1);
       return false;
     } catch (UnsatisfiedLinkError e) {
       logger.fatal("Error when running script: " + e);
+      System.exit(1);
       return false;
     } catch (SimulationCreationException e) {
+      System.exit(1);
       logger.fatal("Error when running script: " + e);
       return false;
     }