diff --git a/docs/userguide.rst b/docs/userguide.rst
index b0d82a8..7c15c56 100644
--- a/docs/userguide.rst
+++ b/docs/userguide.rst
@@ -74,6 +74,7 @@ Environment variables
 | ``KAS_DISTRO``        | This overwrites the respective setting in the       |
 | ``KAS_MACHINE``       | configuration file.                                 |
 | ``KAS_TARGET``        |                                                     |
+| ``KAS_TASK``          |                                                     |
 +-----------------------+-----------------------------------------------------+
 | ``SSH_PRIVATE_KEY``   | Path to the private key file that should be added   |
 |                       | to an internal ssh-agent. This key cannot be        |
@@ -298,6 +299,10 @@ Static configuration reference
     Contains the target to build by bitbake. Can be overwritten by the
     ``KAS_TARGET`` environment variable and defaults to ``core-image-minimal``.
 
+* ``task``: string [optional]
+    Contains the task to build by bitbake. Can be overwritten by the
+    ``KAS_TASK`` environment variable and defaults to ``build``.
+
 * ``repos``: dict [optional]
     Contains the definitions of all available repos and layers.
 
diff --git a/kas/build.py b/kas/build.py
index ad343f2..e10024f 100644
--- a/kas/build.py
+++ b/kas/build.py
@@ -57,8 +57,7 @@ class Build:
         bld_psr.add_argument('--target',
                              help='Select target to build')
         bld_psr.add_argument('--task',
-                             help='Select which task should be executed',
-                             default='build')
+                             help='Select which task should be executed')
         bld_psr.add_argument('--skip',
                              help='Skip build steps',
                              default=[])
@@ -72,7 +71,7 @@ class Build:
         if args.cmd != 'build':
             return False
 
-        cfg = load_config(args.config, args.target)
+        cfg = load_config(args.config, args.target, args.task)
 
         macro = Macro()
 
@@ -119,5 +118,6 @@ class BuildCommand(Command):
         """
         # Start bitbake build of image
         bitbake = find_program(config.environ['PATH'], 'bitbake')
-        run_cmd([bitbake, '-k', config.get_bitbake_target(), '-c', self.task],
+        run_cmd([bitbake, '-k', config.get_bitbake_target(),
+                 '-c', config.get_bitbake_task()],
                 env=config.environ, cwd=config.build_dir)
diff --git a/kas/config.py b/kas/config.py
index ba94967..c6944a5 100644
--- a/kas/config.py
+++ b/kas/config.py
@@ -149,6 +149,13 @@ class Config:
                               self._config.get('target',
                                                'core-image-minimal'))
 
+    def get_bitbake_task(self):
+        """
+            Return the bitbake task
+        """
+        return os.environ.get('KAS_TASK',
+                              self._config.get('task', 'build'))
+
     def _get_conf_header(self, header_name):
         """
             Returns the local.conf header
@@ -195,7 +202,7 @@ class ConfigPython(Config):
     """
         Implementation of a configuration that uses a Python script.
     """
-    def __init__(self, filename, target):
+    def __init__(self, filename, target, task):
         # pylint: disable=exec-used
 
         super().__init__()
@@ -210,11 +217,12 @@ class ConfigPython(Config):
             raise IOError(errno.ENOENT, os.strerror(errno.ENOENT),
                           self.filename)
 
-        self.create_config(target)
+        self.create_config(target, task)
         self.setup_environ()
 
     def __str__(self):
         output = 'target: {}\n'.format(self.target)
+        output = 'task: {}\n'.format(self.task)
         output += 'repos:\n'
         for repo in self.get_repos():
             output += '  {}\n'.format(repo.__str__())
@@ -244,11 +252,12 @@ class ConfigPython(Config):
         except KeyError:
             return None
 
-    def create_config(self, target):
+    def create_config(self, target, task):
         """
             Sets the configuration for `target`
         """
         self.target = 'core-image-minimal' if target is None else target
+        self.task = 'build' if task is None else task
         self.repos = self._config['get_repos'](self, target)
 
     def get_proxy_config(self):
@@ -323,7 +332,7 @@ class ConfigStatic(Config):
         Implements the static kas configuration based on config files.
     """
 
-    def __init__(self, filename, target):
+    def __init__(self, filename, target, task):
         from .includehandler import GlobalIncludes, IncludeException
         super().__init__()
         self.setup_environ()
@@ -360,6 +369,8 @@ class ConfigStatic(Config):
 
         if target:
             self._config['target'] = target
+        if task:
+            self._config['task'] = task
 
     def get_repos(self):
         """
@@ -421,15 +432,15 @@ class ConfigStatic(Config):
         return repo_dict
 
 
-def load_config(filename, target):
+def load_config(filename, target, task):
     """
         Return configuration generated from `filename`.
     """
 
     (_, ext) = os.path.splitext(filename)
     if ext == '.py':
-        cfg = ConfigPython(filename, target)
+        cfg = ConfigPython(filename, target, task)
     else:
-        cfg = ConfigStatic(filename, target)
+        cfg = ConfigStatic(filename, target, task)
 
     return cfg
diff --git a/kas/shell.py b/kas/shell.py
index fd469f6..3d8e712 100644
--- a/kas/shell.py
+++ b/kas/shell.py
@@ -73,7 +73,7 @@ class Shell:
         if args.cmd != 'shell':
             return False
 
-        cfg = load_config(args.config, args.target)
+        cfg = load_config(args.config, args.target, None)
 
         macro = Macro()