diff --git a/lunchable/models/crypto.py b/lunchable/models/crypto.py
index 8f80731..37cb371 100644
--- a/lunchable/models/crypto.py
+++ b/lunchable/models/crypto.py
@@ -57,7 +57,9 @@ class CryptoObject(LunchableModel):
     )
     currency: Optional[str] = Field(description="Abbreviation for the cryptocurrency")
     status: Optional[str] = Field(description=_status_description)
-    institution_name: str = Field(description="Name of provider holding the asset")
+    institution_name: Optional[str] = Field(
+        default=None, description="Name of provider holding the asset"
+    )
     created_at: datetime.datetime = Field(description=_created_at_description)
 
 
diff --git a/lunchable/models/transactions.py b/lunchable/models/transactions.py
index 50ba10b..bce8a31 100644
--- a/lunchable/models/transactions.py
+++ b/lunchable/models/transactions.py
@@ -185,7 +185,9 @@ class TransactionSplitObject(TransactionBaseObject):
     """
 
     date: datetime.date = Field(description=_date_description)
-    category_id: int = Field(description=_category_id_description)
+    category_id: Optional[int] = Field(
+        default=None, description=_category_id_description
+    )
     notes: Optional[str] = Field(description=_notes_description)
     amount: float = Field(description=_amount_description)