diff --git a/prism/src/simulator/ModulesFileModelGenerator.java b/prism/src/simulator/ModulesFileModelGenerator.java
index 3f48d6d7..ffc0bec1 100644
--- a/prism/src/simulator/ModulesFileModelGenerator.java
+++ b/prism/src/simulator/ModulesFileModelGenerator.java
@@ -468,7 +468,7 @@ public class ModulesFileModelGenerator implements ModelGenerator, RewardGenerato
 						throw new PrismLangException("Reward structure is not finite at state " + state, originalModulesFile.getRewardStruct(r).getReward(i));
 					}
 					if (rew < 0) {
-						throw new PrismLangException("Reward structure is negative + (" + rew + ") at state " + state, originalModulesFile.getRewardStruct(r).getReward(i));
+						// throw new PrismLangException("Reward structure is negative + (" + rew + ") at state " + state, originalModulesFile.getRewardStruct(r).getReward(i));
 					}
 					d += rew;
 				}
@@ -497,7 +497,7 @@ public class ModulesFileModelGenerator implements ModelGenerator, RewardGenerato
 							throw new PrismLangException("Reward structure is not finite at state " + state, originalModulesFile.getRewardStruct(r).getReward(i));
 						}
 						if (rew < 0) {
-							throw new PrismLangException("Reward structure is negative + (" + rew + ") at state " + state, originalModulesFile.getRewardStruct(r).getReward(i));
+							// throw new PrismLangException("Reward structure is negative + (" + rew + ") at state " + state, originalModulesFile.getRewardStruct(r).getReward(i));
 						}
 						d += rew;
 					}