diff --git a/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx b/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx
index eee68c8..5b3a430 100644
--- a/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx
+++ b/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx
@@ -113,7 +113,7 @@ export default function GenerateSlotDefinitionsModal({
     setError(null);
 
     const request: GenerateSlotDefinitionsRequest = {
-      preset,
+      pattern_type: preset,
       court_ids: selectedCourtIds,
       pattern_overrides: buildPatternOverrides(),
     };
diff --git a/src/types/slot-definitions.ts b/src/types/slot-definitions.ts
index 9e4340c..95fb0f8 100644
--- a/src/types/slot-definitions.ts
+++ b/src/types/slot-definitions.ts
@@ -147,7 +147,7 @@ export interface PatternOverrides {
  * Generate endpoint request
  */
 export interface GenerateSlotDefinitionsRequest {
-  preset: SlotDefinitionPreset;
+  pattern_type: SlotDefinitionPreset;
   court_ids: number[];
   pattern_overrides?: PatternOverrides;
   valid_from?: string; // YYYY-MM-DD