diff --git a/packages/gooddata-sdk/src/gooddata_sdk/catalog/workspace/declarative_model/workspace/logical_model/dataset/dataset.py b/packages/gooddata-sdk/src/gooddata_sdk/catalog/workspace/declarative_model/workspace/logical_model/dataset/dataset.py
index 7354c579a..b748c97ae 100644
--- a/packages/gooddata-sdk/src/gooddata_sdk/catalog/workspace/declarative_model/workspace/logical_model/dataset/dataset.py
+++ b/packages/gooddata-sdk/src/gooddata_sdk/catalog/workspace/declarative_model/workspace/logical_model/dataset/dataset.py
@@ -208,8 +208,6 @@ class CatalogDeclarativeReference(Base):
     source_columns: list[str] | None = None
     source_column_data_types: list[str] | None = None
     sources: list[CatalogDeclarativeReferenceSource] | None = None
-    is_nullable: bool | None = None
-    null_value: str | None = None
 
     @staticmethod
     def client_class() -> type[DeclarativeReference]:
@@ -231,6 +229,8 @@ class CatalogDeclarativeReferenceSource(Base):
     column: str
     target: CatalogGrainIdentifier
     data_type: str | None = None
+    is_nullable: bool | None = None
+    null_value: str | None = None
 
     @staticmethod
     def client_class() -> type[DeclarativeReferenceSource]:
diff --git a/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model.yaml b/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model.yaml
index c10391ee5..998a9b507 100644
--- a/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model.yaml
+++ b/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model.yaml
@@ -112,6 +112,7 @@ interactions:
                     sources:
                       - column: campaign_id
                         dataType: INT
+                        isNullable: true
                         target:
                           id: campaign_id
                           type: attribute
@@ -321,6 +322,7 @@ interactions:
                     sources:
                       - column: campaign_id
                         dataType: INT
+                        isNullable: true
                         target:
                           id: campaign_id
                           type: attribute
@@ -331,6 +333,7 @@ interactions:
                     sources:
                       - column: customer_id
                         dataType: INT
+                        isNullable: true
                         target:
                           id: customer_id
                           type: attribute
@@ -341,6 +344,7 @@ interactions:
                     sources:
                       - column: date
                         dataType: DATE
+                        isNullable: true
                         target:
                           id: date
                           type: date
@@ -351,6 +355,7 @@ interactions:
                     sources:
                       - column: product_id
                         dataType: INT
+                        isNullable: true
                         target:
                           id: product_id
                           type: attribute
diff --git a/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model_sql_datasets.yaml b/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model_sql_datasets.yaml
index 17bb9b5cb..265765753 100644
--- a/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model_sql_datasets.yaml
+++ b/packages/gooddata-sdk/tests/catalog/fixtures/data_sources/demo_scan_pdm_and_generate_logical_model_sql_datasets.yaml
@@ -496,7 +496,6 @@ interactions:
                     sources:
                       - column: campaign_id
                         dataType: INT
-                        isNullable: true
                         target:
                           id: campaigns.campaign_id
                           type: attribute
@@ -670,7 +669,6 @@ interactions:
                     sources:
                       - column: campaign_id
                         dataType: INT
-                        isNullable: true
                         target:
                           id: campaigns.campaign_id
                           type: attribute
@@ -681,7 +679,6 @@ interactions:
                     sources:
                       - column: customer_id
                         dataType: INT
-                        isNullable: true
                         target:
                           id: customers.customer_id
                           type: attribute
@@ -692,7 +689,6 @@ interactions:
                     sources:
                       - column: date
                         dataType: DATE
-                        isNullable: true
                         target:
                           id: date
                           type: date
@@ -703,7 +699,6 @@ interactions:
                     sources:
                       - column: product_id
                         dataType: INT
-                        isNullable: true
                         target:
                           id: products.product_id
                           type: attribute