diff --git a/ramalama/common.py b/ramalama/common.py
index 048b9e2b..605eabb9 100644
--- a/ramalama/common.py
+++ b/ramalama/common.py
@@ -26,19 +26,30 @@
 DEFAULT_IMAGE = "quay.io/ramalama/ramalama"
 
 
+_engine = ""
+
+
 def container_manager():
+    global _engine
+    if _engine != "":
+        if _engine == "None":
+            return None
+        return _engine
+
+    _engine = "None"
     engine = os.getenv("RAMALAMA_CONTAINER_ENGINE")
     if engine is not None:
-        return engine
+        _engine = engine
+        return _engine
 
     if available("podman"):
         if sys.platform != "darwin" or is_podman_machine_running_with_krunkit():
-            return "podman"
-
-        return None
+            _engine = "podman"
+        return _engine
 
     if available("docker"):
-        return "docker"
+        _engine = "docker"
+        return _engine
 
     return None
 
diff --git a/ramalama/model.py b/ramalama/model.py
index 802e2e0d..763809bb 100644
--- a/ramalama/model.py
+++ b/ramalama/model.py
@@ -188,11 +188,11 @@ def setup_container(self, args):
             conman_args += ["-p", f"{args.port}:{args.port}"]
 
         # Check for env var RAMALAMA_DEVICE to explicitly declare the GPU device path
-        device_override=0
+        device_override = 0
         gpu_device = os.environ.get("RAMALAMA_DEVICE")
         if gpu_device:
             conman_args += ["--device", gpu_device]
-            device_override=1
+            device_override = 1
         if device_override != 1:
             if (sys.platform == "darwin" and os.path.basename(args.engine) != "docker") or os.path.exists("/dev/dri"):
                 conman_args += ["--device", "/dev/dri"]
diff --git a/ramalama/ollama.py b/ramalama/ollama.py
index b80a8922..75378a64 100644
--- a/ramalama/ollama.py
+++ b/ramalama/ollama.py
@@ -64,10 +64,10 @@ def init_pull(repos, accept, registry_head, model_name, model_tag, models, model
 def in_existing_cache(model_name, model_tag):
     if not available("ollama"):
         return None
-    default_ollama_caches=[
+    default_ollama_caches = [
         os.path.join(os.environ['HOME'], '.ollama/models'),
         '/usr/share/ollama/.ollama/models',
-        f'C:\\Users\\{os.getlogin()}\\.ollama\\models'
+        f'C:\\Users\\{os.getlogin()}\\.ollama\\models',
     ]
 
     for cache_dir in default_ollama_caches:
@@ -79,10 +79,11 @@ def in_existing_cache(model_name, model_tag):
                     if layer["mediaType"] == "application/vnd.ollama.image.model":
                         layer_digest = layer["digest"]
                         ollama_digest_path = os.path.join(cache_dir, 'blobs', layer_digest)
-                        if os.path.exists(str(ollama_digest_path).replace(':','-')):
-                          return str(ollama_digest_path).replace(':','-')
+                        if os.path.exists(str(ollama_digest_path).replace(':', '-')):
+                            return str(ollama_digest_path).replace(':', '-')
     return None
 
+
 class Ollama(Model):
     def __init__(self, model):
         model = rm_until_substring(model, "ollama.com/library/")