diff --git a/prism/src/prism/UndefinedConstants.java b/prism/src/prism/UndefinedConstants.java
index b4eb353a..c03ff737 100644
--- a/prism/src/prism/UndefinedConstants.java
+++ b/prism/src/prism/UndefinedConstants.java
@@ -377,7 +377,6 @@ public class UndefinedConstants
 				pfConsts[index].define(sl, sh, ss);
 			}
 			else {
-				System.out.println("XXX: " + name);
 				if (useAll)
 					throw new PrismException("\"" + name + "\" is not an undefined constant");
 			}
diff --git a/prism/src/simulator/SimulatorEngine.java b/prism/src/simulator/SimulatorEngine.java
index 439704b7..a3b93fbf 100644
--- a/prism/src/simulator/SimulatorEngine.java
+++ b/prism/src/simulator/SimulatorEngine.java
@@ -272,7 +272,6 @@ public class SimulatorEngine
 		switch (modelType) {
 		case DTMC:
 		case MDP:
-		case PTA:
 			// Pick a random choice
 			i = rng.randomUnifInt(numChoices);
 			choice = transitionList.getChoice(i);
@@ -597,9 +596,9 @@ public class SimulatorEngine
 		this.mfConstants = modulesFile.getConstantValues();
 
 		// Check for PTAs
-		/*if (modulesFile.getModelType() == ModelType.PTA) {
+		if (modulesFile.getModelType() == ModelType.PTA) {
 			throw new PrismException("Sorry - the simulator does not currently support PTAs");
-		}*/
+		}
 
 		// Check for presence of system...endsystem
 		if (modulesFile.getSystemDefn() != null) {
@@ -1353,7 +1352,7 @@ public class SimulatorEngine
 		for (int i = 0; i < n; i++) {
 			definedPFConstants = undefinedConstants.getPFConstantValues();
 			pfcs[i] = definedPFConstants;
-			propertiesFile.setSomeUndefinedConstants(definedPFConstants);
+			propertiesFile.setUndefinedConstants(definedPFConstants);
 			try {
 				checkPropertyForSimulation(expr);
 				indices[i] = addProperty(expr, propertiesFile);