diff --git a/interpreter/src/main/java/org/intocps/maestro/interpreter/extensions/fmi3/Fmi3Interpreter.java b/interpreter/src/main/java/org/intocps/maestro/interpreter/extensions/fmi3/Fmi3Interpreter.java
index 3f37be9a..632d1b75 100644
--- a/interpreter/src/main/java/org/intocps/maestro/interpreter/extensions/fmi3/Fmi3Interpreter.java
+++ b/interpreter/src/main/java/org/intocps/maestro/interpreter/extensions/fmi3/Fmi3Interpreter.java
@@ -523,9 +523,9 @@ private static Value getFmuInstanceValue(BufferedOutputStream fmuLogOutputStream
         }));
 
         functions.put("updateDiscreteStates", new FunctionValue.ExternalFunctionValue(fcargs -> {
-//            int updateDiscreteStates(bool[] discreteStatesNeedUpdate, bool[] terminateSimulation,
-//                    bool[] nominalsOfContinuousStatesChanged, bool[] valuesOfContinuousStatesChanged, bool[] nextEventTimeDefined,
-//                    real[] nextEventTime);
+//            int updateDiscreteStates(out bool[] discreteStatesNeedUpdate, out bool[] terminateSimulation,
+//            out bool[] nominalsOfContinuousStatesChanged, out bool[] valuesOfContinuousStatesChanged, out bool[] nextEventTimeDefined,
+//            out real[] nextEventTime);
             checkArgLength(fcargs, 6);
             try {
                 FmuResult<IFmi3Instance.UpdateDiscreteStates> res = instance.updateDiscreteStates();
diff --git a/typechecker/src/main/resources/org/intocps/maestro/typechecker/FMI3.mabl b/typechecker/src/main/resources/org/intocps/maestro/typechecker/FMI3.mabl
index cc552755..d84495ec 100644
--- a/typechecker/src/main/resources/org/intocps/maestro/typechecker/FMI3.mabl
+++ b/typechecker/src/main/resources/org/intocps/maestro/typechecker/FMI3.mabl
@@ -216,9 +216,9 @@ module FMI3Instance import FMU3State;{
         /* end::EvaluateDiscreteStates[] */
     
         /* tag::UpdateDiscreteStates[] */
-        int updateDiscreteStates(bool[] discreteStatesNeedUpdate, bool[] terminateSimulation,
-                bool[] nominalsOfContinuousStatesChanged, bool[] valuesOfContinuousStatesChanged, bool[] nextEventTimeDefined,
-                real[] nextEventTime);
+        int updateDiscreteStates(out bool[] discreteStatesNeedUpdate, out bool[] terminateSimulation,
+                out bool[] nominalsOfContinuousStatesChanged, out bool[] valuesOfContinuousStatesChanged, out bool[] nextEventTimeDefined,
+                out real[] nextEventTime);
         /* end::UpdateDiscreteStates[] */
     
         /***************************************************