diff --git a/source/module/actors/M5ModAggregate.ts b/source/module/actors/M5ModAggregate.ts
index cd492ed..702d52b 100644
--- a/source/module/actors/M5ModAggregate.ts
+++ b/source/module/actors/M5ModAggregate.ts
@@ -126,7 +126,7 @@ export default class M5ModAggregate {
 			if (mods.length !== 0) {
 				ret.mods = ret.mods.concat(mods.map(this.pairAsSource));
 				const bonus = mods.map((p) => p.mod.value).reduce((a, b) => a + b, 0);
-				ret.value = ret.value + bonus;
+				ret.value = Math.max(0, ret.value + bonus);
 			}
 
 			mods = arr.filter((pair) => pair.mod.operation === M5ModOperation.SUBTRACT);