diff --git a/Dockerfile b/Dockerfile
index 4ca00d254b..3044749854 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,13 +24,15 @@ FROM alpine
 MAINTAINER www.evennia.com
 
 # install compilation environment
-RUN apk update && apk add python py-pip python-dev py-setuptools gcc musl-dev jpeg-dev zlib-dev bash
+RUN apk update && apk add python py-pip python-dev py-setuptools gcc \
+musl-dev jpeg-dev zlib-dev bash py2-openssl procps
 
 # add the project source
 ADD . /usr/src/evennia
 
 # install dependencies
-RUN pip install --upgrade pip && pip install /usr/src/evennia --trusted-host pypi.python.org
+RUN pip install --upgrade pip && pip install -e /usr/src/evennia --trusted-host pypi.python.org
+RUN pip install cryptography pyasn1 service_identity
 
 # add the game source when rebuilding a new docker image from inside
 # a game dir
diff --git a/evennia/commands/cmdset.py b/evennia/commands/cmdset.py
index c363f87f80..6f127da1c2 100644
--- a/evennia/commands/cmdset.py
+++ b/evennia/commands/cmdset.py
@@ -296,9 +296,9 @@ class CmdSet(with_metaclass(_CmdSetMeta, object)):
             result (any): An instantiated Command or the input unmodified.
 
         """
-        try:
+        if callable(cmd):
             return cmd()
-        except TypeError:
+        else:
             return cmd
 
     def _duplicate(self):