diff --git a/libs/ktem/ktem/index/file/index.py b/libs/ktem/ktem/index/file/index.py
index 2f1bc8a..0cbd57f 100644
--- a/libs/ktem/ktem/index/file/index.py
+++ b/libs/ktem/ktem/index/file/index.py
@@ -115,7 +115,7 @@ class FileIndex(BaseIndex):
                 "id": Column(Integer, primary_key=True, autoincrement=True),
                 "source_id": Column(String),
                 "target_id": Column(String),
-                "relation_type": Column(Integer),
+                "relation_type": Column(String),
                 "user": Column(Integer, default=1),
             },
         )
diff --git a/scripts/migrate/migrate_chroma_db.py b/scripts/migrate/migrate_chroma_db.py
index 96fa920..adffca0 100644
--- a/scripts/migrate/migrate_chroma_db.py
+++ b/scripts/migrate/migrate_chroma_db.py
@@ -83,7 +83,7 @@ def _init_resource(private: bool = True, id: int = 1):
             "id": Column(Integer, primary_key=True, autoincrement=True),
             "source_id": Column(String),
             "target_id": Column(String),
-            "relation_type": Column(Integer),
+            "relation_type": Column(String),
             "user": Column(Integer, default=1),
         },
     )