diff --git a/prism/src/param/ModelBuilder.java b/prism/src/param/ModelBuilder.java
index e9d48b0e..a378a252 100644
--- a/prism/src/param/ModelBuilder.java
+++ b/prism/src/param/ModelBuilder.java
@@ -322,7 +322,7 @@ public final class ModelBuilder extends PrismComponent
 
 		while (!explore.isEmpty()) {
 			state = explore.removeFirst();
-			TransitionList tranlist = engine.calculateTransitions(state);
+			TransitionList tranlist = engine.calculateTransitions(state, true);  // Suppress warnings
 			int numChoices = tranlist.getNumChoices();
 			if (isNonDet) {
 				numTotalChoices += numChoices;
@@ -394,7 +394,7 @@ public final class ModelBuilder extends PrismComponent
 		model.addInitialState(permut[0]);
 		int stateNr = 0;
 		for (State state : statesList) {
-			TransitionList tranlist = engine.calculateTransitions(state);
+			TransitionList tranlist = engine.calculateTransitions(state, false);
 			int numChoices = tranlist.getNumChoices();
 
 			boolean computeSumOut = !isNonDet;
diff --git a/prism/src/param/SymbolicEngine.java b/prism/src/param/SymbolicEngine.java
index dc314257..8b16008c 100644
--- a/prism/src/param/SymbolicEngine.java
+++ b/prism/src/param/SymbolicEngine.java
@@ -70,6 +70,9 @@ public class SymbolicEngine
 	protected ModelBuilder modelBuilder;
 	protected FunctionFactory functionFactory;
 
+	//  flag that suppresses warnings during calculateTransitions
+	private boolean noWarnings = false;
+
 	public SymbolicEngine(ModulesFile modulesFile, ModelBuilder modelBuilder, FunctionFactory functionFactory)
 	{
 		this.modelBuilder = modelBuilder;
@@ -137,12 +140,14 @@ public class SymbolicEngine
 		}
 	}
 	
-	public TransitionList calculateTransitions(State state) throws PrismException
+	public TransitionList calculateTransitions(State state, boolean noWarnings) throws PrismException
 	{
 		List<ChoiceListFlexi> chs;
 		int i, j, k, l, n, count;
 		TransitionList transitionList = new TransitionList();
 
+		this.noWarnings = noWarnings;
+
 		// Clear lists/bitsets
 		transitionList.clear();
 		for (i = 0; i < numModules; i++) {
@@ -295,6 +300,8 @@ public class SymbolicEngine
 				Function pFn = modelBuilder.expr2function(functionFactory, p);
 				if (pFn.isZero()) {
 					// function for probability / rate is zero, don't add the corresponding transition
+					if (!noWarnings)
+						modelBuilder.getLog().printWarning("Update has zero " + (modelType.continuousTime() ? "rate" : "probability") + " (" + p + (p.hasPosition() ? ", " + p.getBeginString() : "") +")");
 					continue;
 				}
 				ch.add(pFn, list);