diff --git a/source/components/conversation/select/Select.js b/source/components/conversation/select/SelectGéo.js
similarity index 80%
rename from source/components/conversation/select/Select.js
rename to source/components/conversation/select/SelectGéo.js
index 82807388d..ab8336113 100644
--- a/source/components/conversation/select/Select.js
+++ b/source/components/conversation/select/SelectGéo.js
@@ -8,7 +8,9 @@ import './Select.css'
 let getOptions = input =>
 	input.length < 3
 		? Promise.resolve({ options: [] })
-		: fetch(`https://geo.api.gouv.fr/communes?nom=${input}`)
+		: fetch(
+				`https://geo.api.gouv.fr/communes?nom=${input}&fields=nom,code,departement,region&`
+		  )
 				.then(response => {
 					if (!response.ok)
 						return [{ nom: 'Aucune commune trouvée', disabled: true }]
@@ -31,7 +33,8 @@ export default class Select extends Component {
 				submit
 			} = this.props,
 			submitOnChange = option => {
-				onChange(option)
+				// serialize to not mix our data schema and the API response's
+				onChange(JSON.stringify(option))
 				submit()
 			}
 
@@ -40,8 +43,8 @@ export default class Select extends Component {
 				<ReactSelect.Async
 					onChange={submitOnChange}
 					labelKey="nom"
-					optionRenderer={({ nom, codeDepartement }) =>
-						nom + ` (${codeDepartement})`
+					optionRenderer={({ nom, departement }) =>
+						nom + ` (${departement.nom})`
 					}
 					placeholder="Entrez le nom de commune"
 					noResultsText="Nous n'avons trouvé aucune commune"
diff --git a/source/engine/generateQuestions.js b/source/engine/generateQuestions.js
index e1b72b21a..30eceb254 100644
--- a/source/engine/generateQuestions.js
+++ b/source/engine/generateQuestions.js
@@ -22,7 +22,7 @@ import {
 import React from 'react'
 import Question from 'Components/conversation/Question'
 import Input from 'Components/conversation/Input'
-import Select from 'Components/conversation/select/Select'
+import SelectGéo from 'Components/conversation/select/SelectGéo'
 import SelectAtmp from 'Components/conversation/select/SelectTauxRisque'
 import formValueTypes from 'Components/conversation/formValueTypes'
 
@@ -116,6 +116,9 @@ export let getInputComponent = rules => dottedName => {
 				}}
 			/>
 		)
+	if (rule.API && rule.API === 'géo')
+		return <SelectGéo {...{ ...commonProps }} />
+	if (rule.API) throw new Error("Le seul API implémenté est l'API géo")
 
 	if (rule.format == null)
 		return (
@@ -141,10 +144,6 @@ export let getInputComponent = rules => dottedName => {
 			/>
 		)
 
-	if (rule.api && rule.api == 'géo') return <Select {...{ commonProps }} />
-
-	if (rule.api) throw new Error("Le seul API implémenté est l'API géo")
-
 	// Now the numeric input case
 
 	return (
diff --git a/source/engine/mecanisms.js b/source/engine/mecanisms.js
index 236cffa5d..58d620254 100644
--- a/source/engine/mecanisms.js
+++ b/source/engine/mecanisms.js
@@ -974,11 +974,13 @@ export let mecanismSynchronisation = (recurse, k, v) => {
 			parsedRules,
 			node.explanation.API
 		)
+
 		let nodeValue =
 			val(APIExplanation) == null
 				? null
-				: path(v.chemin.split(' . '))(val(APIExplanation))
-		let missingVariables = APIExplanation.nodeValue === null ? [v.API] : []
+				: path(v.chemin.split(' . '))(JSON.parse(val(APIExplanation)))
+		let missingVariables =
+			val(APIExplanation) === null ? { [APIExplanation.dottedName]: 1 } : {}
 		let explanation = { ...v, API: APIExplanation }
 		return rewriteNode(node, nodeValue, explanation, missingVariables)
 	}
@@ -986,7 +988,7 @@ export let mecanismSynchronisation = (recurse, k, v) => {
 	return {
 		explanation: { ...v, API: recurse(v.API) },
 		evaluate,
-		jsx: () => <span>API</span>,
+		jsx: (nodeValue, explanation) => <span>{nodeValue}</span>,
 		category: 'mecanism',
 		name: 'synchronisation'
 	}
diff --git a/source/engine/rules.js b/source/engine/rules.js
index f2f7fba15..e1aecbc66 100644
--- a/source/engine/rules.js
+++ b/source/engine/rules.js
@@ -86,8 +86,15 @@ export let hasKnownRuleType = rule => rule && enrichRule(rule).type
 export let splitName = split(' . '),
 	joinName = join(' . ')
 
-export let parentName = pipe(splitName, dropLast(1), joinName)
-export let nameLeaf = pipe(splitName, last)
+export let parentName = pipe(
+	splitName,
+	dropLast(1),
+	joinName
+)
+export let nameLeaf = pipe(
+	splitName,
+	last
+)
 
 export let encodeRuleName = name =>
 	name.replace(/\s\.\s/g, '--').replace(/\s/g, '-')