diff --git a/ceci/pipeline.py b/ceci/pipeline.py
index 1551034..77cd489 100644
--- a/ceci/pipeline.py
+++ b/ceci/pipeline.py
@@ -5,7 +5,7 @@
 import collections
 import yaml
 import shutil
-from abc import abstractmethod
+from abc import ABC, abstractmethod
 
 from .stage import PipelineStage
 from . import minirunner
@@ -286,7 +286,7 @@ def insert_outputs(self, stage, outdir):
         return stage_outputs
 
 
-class Pipeline:
+class Pipeline(ABC):
     """
     The Pipeline base class models the shared information and behaviour
     that pipelines need, no matter which workflow manager runs them.
diff --git a/ceci/stage.py b/ceci/stage.py
index 1915a93..ef60287 100644
--- a/ceci/stage.py
+++ b/ceci/stage.py
@@ -9,7 +9,7 @@
 import pdb
 import datetime
 
-from abc import abstractmethod
+from abc import ABC, abstractmethod
 from . import errors
 from .monitor import MemoryMonitor
 from .config import StageParameter, StageConfig, cast_to_streamable
@@ -21,7 +21,7 @@
 IN_PROGRESS_PREFIX = "inprogress_"
 
 
-class PipelineStage:
+class PipelineStage(ABC):
     """A PipelineStage implements a single calculation step within a wider pipeline.
 
     Each different type of analysis stage is represented by a subclass of this