diff --git a/src/apis/solverapi.py b/src/apis/solverapi.py
index 54f2abb..1f4c9fe 100644
--- a/src/apis/solverapi.py
+++ b/src/apis/solverapi.py
@@ -28,7 +28,7 @@ def __init__(self, url: Optional[str] = None) -> None:
             load_dotenv()
             self.solver_url = getenv("QUASIMODO_SOLVER_URL")
             if self.solver_url is not None:
-                self.solver_url.replace("prod", "staging")
+                self.solver_url = self.solver_url.replace("prod", "staging")
 
     def solve_instance(
         self, auction_instance: dict[str, Any]