diff --git a/api/src/engine/connectors/exareme/transformations.ts b/api/src/engine/connectors/exareme/transformations.ts
index a57e677bf1e341a527f2c98c105376135c6a4339..75175baa50979b9f3665ab37af65de95f48e5506 100644
--- a/api/src/engine/connectors/exareme/transformations.ts
+++ b/api/src/engine/connectors/exareme/transformations.ts
@@ -52,7 +52,7 @@ export const transformToExperiment = jsonata(`
                 algorithm.parameters[$not(name in $params)].({
                     "name": name,
                     "label": label,
-                    "value": value
+                    "value": $split(value, ',')
                 })
         }
     }
diff --git a/api/src/schema.gql b/api/src/schema.gql
index 1d30677261172d7d7fdc830d938d329d9b5f2d5d..2c77f09a4b4718306208679fd8f17fb8c7f39598 100644
--- a/api/src/schema.gql
+++ b/api/src/schema.gql
@@ -86,9 +86,9 @@ type GroupsResult {
 
 type HeatMapResult {
   name: String!
+  xAxis: ChartAxis
+  yAxis: ChartAxis
   matrix: [[Float!]!]!
-  xAxis: ChartAxis!
-  yAxis: ChartAxis!
 }
 
 type LineChartResult {