diff --git a/endpoint/src/datamodel.rs b/endpoint/src/datamodel.rs
index 9f6b353..f33e4be 100644
--- a/endpoint/src/datamodel.rs
+++ b/endpoint/src/datamodel.rs
@@ -52,7 +52,8 @@ pub struct CarbonFootprint {
     pub declared_unit: DeclaredUnit,
     pub unitary_product_amount: StrictlyPositiveDecimal,
     pub p_cf_excluding_biogenic: PositiveDecimal,
-    pub p_cf_including_biogenic: WrappedDecimal,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub p_cf_including_biogenic: Option<WrappedDecimal>,
     pub fossil_ghg_emissions: PositiveDecimal,
     pub fossil_carbon_content: PositiveDecimal,
     pub biogenic_carbon_content: PositiveDecimal,
@@ -86,7 +87,6 @@ pub struct CarbonFootprint {
     pub reference_period_start: DateTime<Utc>,
     pub reference_period_end: DateTime<Utc>,
 
-    #[serde(flatten)]
     #[serde(skip_serializing_if = "Option::is_none")]
     pub geographic_scope: Option<GeographicScope>,
 
diff --git a/endpoint/src/sample_data.rs b/endpoint/src/sample_data.rs
index bbff189..1ebf5eb 100644
--- a/endpoint/src/sample_data.rs
+++ b/endpoint/src/sample_data.rs
@@ -56,7 +56,7 @@ lazy_static! {
         packaging_emissions_included: false,
         packaging_ghg_emissions: None,
         p_cf_excluding_biogenic: dec!(0.0).into(),
-        p_cf_including_biogenic: dec!(0.0).into(),
+        p_cf_including_biogenic: Some(dec!(0.0).into()),
         uncertainty_assessment_description: None,
     };
 }