diff --git a/prism/src/explicit/rewards/ConstructRewards.java b/prism/src/explicit/rewards/ConstructRewards.java
index b14485dd..e19e77a0 100644
--- a/prism/src/explicit/rewards/ConstructRewards.java
+++ b/prism/src/explicit/rewards/ConstructRewards.java
@@ -230,6 +230,11 @@ public class ConstructRewards
 	 */
 	public MCRewards buildMCRewardStructure(DTMC mc, ModelGenerator modelGen, int r) throws PrismException
 	{
+		if (modelGen.rewardStructHasTransitionRewards(r)) {
+			// TODO
+			throw new PrismNotSupportedException("Explicit engine does not yet handle transition rewards for D/CTMCs");
+		}
+
 		int numStates = mc.getNumStates();
 		List<State> statesList = mc.getStatesList();
 		StateRewardsArray rewSA = new StateRewardsArray(numStates);
diff --git a/prism/src/parser/ast/ModulesFile.java b/prism/src/parser/ast/ModulesFile.java
index b3bab3c6..9faaf519 100644
--- a/prism/src/parser/ast/ModulesFile.java
+++ b/prism/src/parser/ast/ModulesFile.java
@@ -1183,6 +1183,13 @@ public class ModulesFile extends ASTElement implements ModelInfo
 		findAllVars(varNames, varTypes);
 	}
 
+	@Override
+	public boolean rewardStructHasTransitionRewards(int i)
+	{
+		RewardStruct rewStr = getRewardStruct(i);
+		return rewStr.getNumTransItems() > 0;
+	}
+
 	/**
 	 * Create a VarList object storing information about all variables in this model.
 	 * Assumes that values for constants have been provided for the model.
diff --git a/prism/src/prism/ModelInfo.java b/prism/src/prism/ModelInfo.java
index 440a7a93..c826737b 100644
--- a/prism/src/prism/ModelInfo.java
+++ b/prism/src/prism/ModelInfo.java
@@ -138,7 +138,14 @@ public interface ModelInfo
 	 * Returns null if index is out of range.
 	 */
 	public RewardStruct getRewardStruct(int i);
-	
+
+	/**
+	 * Returns true if the reward structure with index i
+	 * (indexed from 0, not from 1 like at the user (property language) level)
+	 * defines transition rewards.
+	 */
+	public boolean rewardStructHasTransitionRewards(int i);
+
 	// TODO: can we remove this?
 	public VarList createVarList() throws PrismException;
 }
diff --git a/prism/src/prism/TestModelGenerator.java b/prism/src/prism/TestModelGenerator.java
index aee2db90..8721986e 100644
--- a/prism/src/prism/TestModelGenerator.java
+++ b/prism/src/prism/TestModelGenerator.java
@@ -164,6 +164,12 @@ public class TestModelGenerator extends DefaultModelGenerator
 		}
 	}
 
+	@Override
+	public boolean rewardStructHasTransitionRewards(int i)
+	{
+		return false;
+	}
+
 	@Override
 	public VarList createVarList()
 	{
diff --git a/prism/src/simulator/ModulesFileModelGenerator.java b/prism/src/simulator/ModulesFileModelGenerator.java
index e102dfb6..3dc753b8 100644
--- a/prism/src/simulator/ModulesFileModelGenerator.java
+++ b/prism/src/simulator/ModulesFileModelGenerator.java
@@ -414,4 +414,10 @@ public class ModulesFileModelGenerator extends DefaultModelGenerator
 		}
 		return transitionList;
 	}
+
+	@Override
+	public boolean rewardStructHasTransitionRewards(int i)
+	{
+		return modulesFile.rewardStructHasTransitionRewards(i);
+	}
 }
diff --git a/prism/src/simulator/ModulesFileModelGeneratorSymbolic.java b/prism/src/simulator/ModulesFileModelGeneratorSymbolic.java
index dd620b0d..718e81a0 100644
--- a/prism/src/simulator/ModulesFileModelGeneratorSymbolic.java
+++ b/prism/src/simulator/ModulesFileModelGeneratorSymbolic.java
@@ -462,4 +462,10 @@ public class ModulesFileModelGeneratorSymbolic extends DefaultModelGenerator imp
 		}
 		return constantList.getConstant(i);
 	}
+
+	@Override
+	public boolean rewardStructHasTransitionRewards(int i)
+	{
+		return modulesFile.rewardStructHasTransitionRewards(i);
+	}
 }