diff --git a/chatnoir_api/model/result.py b/chatnoir_api/model/result.py
index 5fa419e..179178a 100644
--- a/chatnoir_api/model/result.py
+++ b/chatnoir_api/model/result.py
@@ -22,7 +22,7 @@
 class MinimalResult(ABC):
     score: float
     uuid: UUID
-    target_uri: str | None
+    target_uri: Optional[str]
     snippet: HighlightedText
     index: Index
     title: HighlightedText
diff --git a/chatnoir_api/v1/model.py b/chatnoir_api/v1/model.py
index 64dafb1..a29282f 100644
--- a/chatnoir_api/v1/model.py
+++ b/chatnoir_api/v1/model.py
@@ -43,7 +43,7 @@ class PhraseRequest(Request, DataClassJsonMixin):
 class MinimalResultResponse(MinimalResult, DataClassJsonMixin):
     score: float
     uuid: UUID = field(metadata=config(decoder=decode_uuid))
-    target_uri: str | None
+    target_uri: Optional[str]
     snippet: HighlightedText = field(metadata=config(decoder=HighlightedText))
     index: Index = field(metadata=config(decoder=parse_index))
     title: HighlightedText = field(