diff --git a/prism/src/explicit/MDP.java b/prism/src/explicit/MDP.java
index fb8c98f6..0b5e2ee2 100644
--- a/prism/src/explicit/MDP.java
+++ b/prism/src/explicit/MDP.java
@@ -39,11 +39,6 @@ import explicit.rewards.MDPRewards;
  */
 public interface MDP extends NondetModel
 {
-	/**
-	 * Get the number of transitions from choice {@code i} of state {@code s}.
-	 */
-	public int getNumTransitions(int s, int i);
-
 	/**
 	 * Get an iterator over the transitions from choice {@code i} of state {@code s}.
 	 */
diff --git a/prism/src/explicit/NondetModel.java b/prism/src/explicit/NondetModel.java
index 02b1fbeb..3cc9a9cd 100644
--- a/prism/src/explicit/NondetModel.java
+++ b/prism/src/explicit/NondetModel.java
@@ -27,12 +27,8 @@
 package explicit;
 
 import java.util.BitSet;
-import java.util.Iterator;
-import java.util.Map.Entry;
 
-import prism.PrismException;
 import prism.PrismLog;
-
 import strat.MDStrategy;
 
 /**
@@ -67,6 +63,11 @@ public interface NondetModel extends Model
 	 */
 	public boolean areAllChoiceActionsUnique();
 	
+	/**
+	 * Get the number of transitions from choice {@code i} of state {@code s}.
+	 */
+	public int getNumTransitions(int s, int i);
+	
 	/**
 	 * Check if all the successor states from choice {@code i} of state {@code s} are in the set {@code set}.
 	 * @param s The state to check
@@ -86,7 +87,7 @@ public interface NondetModel extends Model
 	/**
 	 * Get an iterator over the transitions of state s and action i.
 	 */
-	public Iterator<Entry<Integer, Double>> getTransitionsIterator(int s, int i);
+	//public Iterator<Entry<Integer, Double>> getTransitionsIterator(int s, int i);
 	
 	/**
 	 * Construct a model that is induced by applying strategy {@code strat} to this model.
diff --git a/prism/src/explicit/SubNondetModel.java b/prism/src/explicit/SubNondetModel.java
index ade6b67b..d8773e39 100644
--- a/prism/src/explicit/SubNondetModel.java
+++ b/prism/src/explicit/SubNondetModel.java
@@ -34,7 +34,6 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import parser.State;
 import parser.Values;
@@ -150,8 +149,7 @@ public class SubNondetModel implements NondetModel
 	@Override
 	public List<State> getStatesList()
 	{
-		//We use lazy generation because in many cases the state list is not 
-		//needed
+		// We use lazy generation because in many cases the state list is not needed
 		if (statesList == null) {
 			statesList = generateSubStateList(states);
 		}
@@ -191,14 +189,13 @@ public class SubNondetModel implements NondetModel
 	public Iterator<Integer> getSuccessorsIterator(int s)
 	{
 		s = translateState(s);
-
 		List<Integer> succ = new ArrayList<Integer>();
 		for (int i = 0; i < model.getNumChoices(s); i++) {
 			if (actions.get(s).get(i)) {
-				Iterator<Entry<Integer, Double>> it = model.getTransitionsIterator(s, i);
+				Iterator<Integer> it = model.getSuccessorsIterator(s);
 				while (it.hasNext()) {
-					int succc = it.next().getKey();
-					succ.add(inverseTranslateState(succc));
+					int j = it.next();
+					succ.add(inverseTranslateState(j));
 				}
 			}
 		}
@@ -361,6 +358,14 @@ public class SubNondetModel implements NondetModel
 		throw new RuntimeException("Not implemented");
 	}
 
+	@Override
+	public int getNumTransitions(int s, int i)
+	{
+		s = translateState(s);
+		i = translateAction(s, i);
+		return model.getNumTransitions(s, i);
+	}
+	
 	@Override
 	public boolean allSuccessorsInSet(int s, int i, BitSet set)
 	{
@@ -405,31 +410,13 @@ public class SubNondetModel implements NondetModel
 	{
 		int transitions = 0;
 		for (int i = 0; i < model.getNumChoices(state); i++) {
-			Iterator<Entry<Integer, Double>> it = model.getTransitionsIterator(state, i);
-			while (it.hasNext()) {
-				it.next();
-				transitions += 1;
+			if (actions.get(state).get(i)) {
+				transitions += model.getNumTransitions(state, i);
 			}
 		}
 		return transitions;
 	}
 
-	@Override
-	public Iterator<Entry<Integer, Double>> getTransitionsIterator(int s, int i)
-	{
-		s = translateState(s);
-		i = translateAction(s, i);
-
-		Map<Integer, Double> distrs = new HashMap<Integer, Double>();
-		Iterator<Entry<Integer, Double>> it = model.getTransitionsIterator(s, i);
-		while (it.hasNext()) {
-			Entry<Integer, Double> e = it.next();
-			int succ = inverseTranslateState(e.getKey());
-			distrs.put(succ, e.getValue());
-		}
-		return distrs.entrySet().iterator();
-	}
-
 	@Override
 	public Model constructInducedModel(MDStrategy strat)
 	{