diff --git a/pyentrypoint/command.py b/pyentrypoint/command.py
index e0f747b..71e43d6 100755
--- a/pyentrypoint/command.py
+++ b/pyentrypoint/command.py
@@ -66,7 +66,8 @@ class Command(object):
                     to_del.append(key)
 
         for item in to_del:
-            del(self.env[item])
+            if item in self.env:
+                del(self.env[item])
 
     @property
     def is_handled(self):
diff --git a/setup.py b/setup.py
index b6c04d9..920e9d5 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@ from setuptools import setup
 
 # Thanks Sam and Max
 
-__version__ = '0.5.1'
+__version__ = '0.5.2'
 
 if __name__ == '__main__':
     setup(