diff --git a/runpod/serverless/__init__.py b/runpod/serverless/__init__.py
index aa261b79..62f70722 100644
--- a/runpod/serverless/__init__.py
+++ b/runpod/serverless/__init__.py
@@ -173,13 +173,12 @@ def start(config: Dict[str, Any]):
 
     # --------------------------------- SLS-Core --------------------------------- #
 
-    match os.getenv("RUNPOD_SLS_CORE"):
-        case None if os.getenv("RUNPOD_USE_CORE") is not None:
+    if os.getenv("RUNPOD_SLS_CORE") is None and os.getenv("RUNPOD_USE_CORE") is not None:
             log.warn("RUNPOD_USE_CORE is deprecated. Please use RUNPOD_SLS_CORE instead.")
             core.main(config)
             return
 
-        case x if x.lower() in ["1", "t", "true"]:
+    elif os.getenv("RUNPOD_SLS_CORE","false").lower() in ["1", "t", "true"]:
             core.main(config)
             return