diff --git a/pyproject.toml b/pyproject.toml
index 7863094..1a61798 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,7 +10,7 @@ tokencost = ["model_prices.json"]
 
 [project]
 name = "tokencost"
-version = "0.1.14"
+version = "0.1.15"
 authors = [
   { name = "Trisha Pan", email = "trishaepan@gmail.com" },
   { name = "Alex Reibman", email = "areibman@gmail.com" },
diff --git a/tokencost/constants.py b/tokencost/constants.py
index 31daf7b..083ed9d 100644
--- a/tokencost/constants.py
+++ b/tokencost/constants.py
@@ -46,7 +46,8 @@ async def update_token_costs():
     """Update the TOKEN_COSTS dictionary with the latest costs from the LiteLLM cost tracker asynchronously."""
     global TOKEN_COSTS
     try:
-        TOKEN_COSTS = await fetch_costs()
+        fetched_costs = await fetch_costs()
+        TOKEN_COSTS.update(fetched_costs)
         # Safely remove 'sample_spec' if it exists
         TOKEN_COSTS.pop('sample_spec', None)
     except Exception as e: