diff --git a/src/tag/dto/tag-response.dto.ts b/src/tag/dto/tag-response.dto.ts
index 6a7f94d..d9f9f8a 100644
--- a/src/tag/dto/tag-response.dto.ts
+++ b/src/tag/dto/tag-response.dto.ts
@@ -2,8 +2,8 @@ export type TagItemDto = {
   id: string;
   name: string;
   tagGroup: string | null;
-  min: number;
-  max: number;
+  min: number | null;
+  max: number | null;
   comment: string;
   unitOfMeasurement: string;
   edgeIds: string[];
diff --git a/src/tag/tag.types.ts b/src/tag/tag.types.ts
index b0357b3..751f007 100644
--- a/src/tag/tag.types.ts
+++ b/src/tag/tag.types.ts
@@ -2,8 +2,8 @@ export type TagRow = {
   id: string;
   name: string;
   tag_group: string | null;
-  min: number;
-  max: number;
+  min: number | null;
+  max: number | null;
   comment: string;
   unit_of_measurement: string;
   edge_ids: string[];