diff --git a/prism/src/simulator/sampler/SamplerRewardInstCont.java b/prism/src/simulator/sampler/SamplerRewardInstCont.java
index e87fd11f..8f2c4aae 100644
--- a/prism/src/simulator/sampler/SamplerRewardInstCont.java
+++ b/prism/src/simulator/sampler/SamplerRewardInstCont.java
@@ -45,7 +45,7 @@ public class SamplerRewardInstCont extends SamplerDouble
 	{
 		// Make sure expression is of the correct type
 		// Then extract other required info
-		if (expr.getOperator() != ExpressionTemporal.R_C)
+		if (expr.getOperator() != ExpressionTemporal.R_I)
 			throw new PrismException("Error creating Sampler");
 		time = expr.getUpperBound().evaluateDouble();
 		this.rewardStructIndex = rewardStructIndex;
diff --git a/prism/src/simulator/sampler/SamplerRewardInstDisc.java b/prism/src/simulator/sampler/SamplerRewardInstDisc.java
index ded53d7b..9a4b4395 100644
--- a/prism/src/simulator/sampler/SamplerRewardInstDisc.java
+++ b/prism/src/simulator/sampler/SamplerRewardInstDisc.java
@@ -45,7 +45,7 @@ public class SamplerRewardInstDisc extends SamplerDouble
 	{
 		// Make sure expression is of the correct type
 		// Then extract other required info
-		if (expr.getOperator() != ExpressionTemporal.R_C)
+		if (expr.getOperator() != ExpressionTemporal.R_I)
 			throw new PrismException("Error creating Sampler");
 		time = expr.getUpperBound().evaluateInt();
 		this.rewardStructIndex = rewardStructIndex;