diff --git a/src/snek/system/docker.py b/src/snek/system/docker.py
index 14c6f17..d5e37f9 100644
--- a/src/snek/system/docker.py
+++ b/src/snek/system/docker.py
@@ -165,7 +165,7 @@ class ComposeFileManager:
             return False 
         
         status = await self.get_instance_status(name)
-        if name in self.running_instances and status == "running" and self.running_instances.get(name) and self.running_instances.get(name).get('proc').returncode == 0:
+        if name in self.running_instances and status == "running" and self.running_instances.get(name) and self.running_instances.get(name).get('proc').returncode == None:
             return True 
         elif name in self.running_instances:
             del self.running_instances[name]