diff --git a/pympipool/flux/fluxbroker.py b/pympipool/flux/fluxbroker.py
index 46e6fd76..ac96332f 100644
--- a/pympipool/flux/fluxbroker.py
+++ b/pympipool/flux/fluxbroker.py
@@ -19,6 +19,7 @@ class PyFluxExecutor(ExecutorBase):
         sleep_interval (float): synchronization interval - default 0.1
         executor (flux.job.FluxExecutor): Flux Python interface to submit the workers to flux
     """
+
     def __init__(
         self,
         max_workers,
diff --git a/pympipool/mpi/mpibroker.py b/pympipool/mpi/mpibroker.py
index 4e22459f..76c26797 100644
--- a/pympipool/mpi/mpibroker.py
+++ b/pympipool/mpi/mpibroker.py
@@ -20,6 +20,7 @@ class PyMPIExecutor(ExecutorBase):
         sleep_interval (float): synchronization interval - default 0.1
         enable_slurm_backend (bool): enable the SLURM queueing system as backend - defaults to False
     """
+
     def __init__(
         self,
         max_workers,