diff --git a/publicodes/source/evaluation.tsx b/publicodes/source/evaluation.tsx
index 0f99f60b4..13b9695f7 100644
--- a/publicodes/source/evaluation.tsx
+++ b/publicodes/source/evaluation.tsx
@@ -38,10 +38,7 @@ export const mergeMissing = (left, right) =>
 	mergeWith(add, left || {}, right || {})
 
 export const evaluateNode = (cache, situation, parsedRules, node) => {
-	const evaluatedNode = node.evaluate
-		? node.evaluate(cache, situation, parsedRules, node)
-		: node
-	return evaluatedNode
+	return node.evaluate(cache, situation, parsedRules, node)
 }
 
 function convertNodesToSameUnit(nodes, contextRule, mecanismName) {
@@ -126,14 +123,17 @@ export const evaluateArrayWithFilter = (evaluationFilter, reducer, start) => (
 	)
 }
 
-export const defaultNode = (nodeValue: EvaluatedNode['nodeValue']) => ({
-	nodeValue,
-	// eslint-disable-next-line
-	jsx: ({ nodeValue }: EvaluatedNode) => (
-		<span className="value">{nodeValue}</span>
-	),
-	isDefault: true
-})
+export const defaultNode = (nodeValue: EvaluatedNode['nodeValue']) => {
+	const defaultNode = {
+		nodeValue,
+		// eslint-disable-next-line
+		jsx: ({ nodeValue }: EvaluatedNode) => (
+			<span className="value">{nodeValue}</span>
+		),
+		isDefault: true
+	}
+	return { ...defaultNode, evaluate: () => defaultNode }
+}
 
 export const parseObject = (recurse, objectShape, value) => {
 	const recurseOne = key => defaultValue => {
diff --git a/publicodes/source/mecanisms/reduction.ts b/publicodes/source/mecanisms/reduction.ts
index 238a3efed..b95f6e88e 100644
--- a/publicodes/source/mecanisms/reduction.ts
+++ b/publicodes/source/mecanisms/reduction.ts
@@ -86,7 +86,10 @@ export const mecanismReduction = (recurse, v) => {
 		explanation = v.décote
 			? {
 					...base,
-					décote: map(recurse, v.décote)
+					décote: {
+						...map(recurse, v.décote),
+						evaluate: () => map(recurse, v.décote)
+					}
 			  }
 			: base,
 		evaluate = evaluateObject(objectShape, effect)
diff --git a/publicodes/source/parseRule.tsx b/publicodes/source/parseRule.tsx
index f3ed56685..d5328e3e9 100644
--- a/publicodes/source/parseRule.tsx
+++ b/publicodes/source/parseRule.tsx
@@ -121,6 +121,11 @@ export default function<Names extends string>(
 		defaultValue: value =>
 			typeof value === 'string'
 				? parse(rules, rule, parsedRules)(value)
+				: // TODO : An "object" default value is only used in the
+				// "synchronisation" mecanism. This should be refactored to not use the
+				// attribute "defaultValue"
+				typeof value === 'object'
+				? { ...value, evaluate: () => value }
 				: value,
 		formule: value => {
 			const evaluate = (cache, situation, parsedRules, node) => {