diff --git a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/ports/DatasetsRepository.java b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/ports/DatasetsRepository.java
index 01c643e..3881903 100644
--- a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/ports/DatasetsRepository.java
+++ b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/ports/DatasetsRepository.java
@@ -11,7 +11,6 @@
 public interface DatasetsRepository {
 
     List<SearchedDataset> search(List<String> datasetIds,
-            String returnFields,
             String sort,
             Integer rows,
             Integer start,
diff --git a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/usecases/SearchDatasetsQuery.java b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/usecases/SearchDatasetsQuery.java
index d0fdb0a..922d07b 100644
--- a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/usecases/SearchDatasetsQuery.java
+++ b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/application/usecases/SearchDatasetsQuery.java
@@ -40,7 +40,6 @@ public DatasetsSearchResponse execute(DatasetSearchQuery query, String accessTok
                 .orElse(List.of());
 
         var datasets = repository.search(datasetIds,
-                query.getReturnFields(),
                 query.getSort(),
                 query.getRows(),
                 query.getStart(),
diff --git a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetIdsCollector.java b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetIdsCollector.java
index 2c4ddac..bf49f62 100644
--- a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetIdsCollector.java
+++ b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetIdsCollector.java
@@ -38,10 +38,10 @@ public List<String> collect(DatasetSearchQuery query, String accessToken) {
                 query.getQuery(),
                 facetsQuery,
                 CKAN_IDENTIFIER_FIELD,
-                "",
+                null,
                 CKAN_PAGINATION_MAX_SIZE,
                 0,
-                "",
+                null,
                 accessToken
         );
 
diff --git a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetsRepository.java b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetsRepository.java
index bfd8286..3311cd5 100644
--- a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetsRepository.java
+++ b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanDatasetsRepository.java
@@ -45,7 +45,6 @@ public CkanDatasetsRepository(
 
     @Override
     public List<SearchedDataset> search(List<String> datasetIds,
-            String returnFields,
             String sort,
             Integer rows,
             Integer start,
@@ -71,13 +70,13 @@ public List<SearchedDataset> search(List<String> datasetIds,
                 .build());
 
         var response = ckanQueryApi.packageSearch(
-                "",
+                null,
                 facetsQuery,
-                returnFields,
+                null,
                 sort,
                 rows,
                 start,
-                "",
+                null,
                 accessToken
         );
 
diff --git a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanFacetsBuilder.java b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanFacetsBuilder.java
index bff9eee..63fa51a 100644
--- a/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanFacetsBuilder.java
+++ b/src/main/java/io/github/genomicdatainfrastructure/discovery/datasets/infrastructure/ckan/persistence/CkanFacetsBuilder.java
@@ -41,10 +41,10 @@ public FacetGroup build(DatasetSearchQuery query, String accessToken) {
         var response = ckanQueryApi.packageSearch(
                 query.getQuery(),
                 facetsQuery,
-                query.getReturnFields(),
-                query.getSort(),
-                0,
-                query.getStart(),
+                null,
+                null,
+                null,
+                null,
                 selectedFacets,
                 accessToken
         );
diff --git a/src/main/openapi/discovery.yaml b/src/main/openapi/discovery.yaml
index 12a0421..2643d2c 100644
--- a/src/main/openapi/discovery.yaml
+++ b/src/main/openapi/discovery.yaml
@@ -166,10 +166,6 @@ components:
           title: Facets
           items:
             $ref: "#/components/schemas/DatasetSearchQueryFacet"
-        returnFields:
-          type: string
-          title: dataset fields to return
-          default: "*"
         sort:
           type: string
           title: Sorting of search results