diff --git a/.drone.yml b/.drone.yml
index f625cf40e..4410175b4 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -49,7 +49,7 @@ steps:
 
   commands:
     - echo "Installing required build dependencies"
-    - apk add --update --no-cache make py3-sphinx py3-pip $(cat platypush/install/requirements/alpine.txt)
+    - apk add --update --no-cache make py3-sphinx py3-pip py3-paho-mqtt $(cat platypush/install/requirements/alpine.txt)
     - pip install -U hid sphinx-rtd-theme sphinx-book-theme
     - pip install .
     - mkdir -p /docs/current
diff --git a/platypush/utils/reflection/_parser.py b/platypush/utils/reflection/_parser.py
index 022db2b63..7a1ee01eb 100644
--- a/platypush/utils/reflection/_parser.py
+++ b/platypush/utils/reflection/_parser.py
@@ -99,7 +99,7 @@ class DocstringParser:
     _param_doc_re = re.compile(r"^:param\s+(?P<name>[\w_]+):\s+(?P<doc>.*)$")
     _type_doc_re = re.compile(r"^:type\s+[\w_]+:.*$")
     _return_doc_re = re.compile(r"^:return:\s+(?P<doc>.*)$")
-    _default_docstring = re.compile(r"^Initialize self. See help")
+    _default_docstring = re.compile(r"^\s*Initialize self\. See help.*$")
 
     def __init__(
         self,
@@ -186,7 +186,7 @@ class DocstringParser:
             ctx.cur_param = m.group("name")
 
             # Skip vararg/var keyword parameters
-            if ctx.cur_param == ctx.spec.varkw or ctx.spec.varargs:
+            if ctx.cur_param in {ctx.spec.varkw, ctx.spec.varargs}:
                 return
 
             ctx.parsed_params[ctx.cur_param] = Parameter(