diff --git a/CHANGELOG.md b/CHANGELOG.md
index 28a02b7d6997be81a6e09b3506493e6e5b14846f..cdf3e209c491272b058a4b4f265fd8fec32c4ad7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -43,6 +43,7 @@ re-instantiate the Prior in most cases
 - Users can now choose to overwrite existing result files, rather than creating
   a .old file.
 - Make likelihood values stored in the posterior correct for dynesty and nestle
+- pymultinest output now stored in {outdir}/pm_{label}/
 
 ### Removed
 - Removes the "--detectors" command line argument (not a general CLI requirement)
diff --git a/test/sampler_test.py b/test/sampler_test.py
index 53ec81b109cee30759484bc40624ffd635bab5d9..035d5324dabae6d2f457d4b8144c40409cab9763 100644
--- a/test/sampler_test.py
+++ b/test/sampler_test.py
@@ -360,7 +360,7 @@ class TestPymultinest(unittest.TestCase):
     def test_default_kwargs(self):
         expected = dict(importance_nested_sampling=False, resume=True,
                         verbose=True, sampling_efficiency='parameter',
-                        outputfiles_basename='outdir/pymultinest_label/',
+                        outputfiles_basename='outdir/pm_label/',
                         n_live_points=500, n_params=None,
                         n_clustering_params=None, wrapped_params=None,
                         multimodal=True, const_efficiency_mode=False,
@@ -374,7 +374,7 @@ class TestPymultinest(unittest.TestCase):
     def test_translate_kwargs(self):
         expected = dict(importance_nested_sampling=False, resume=True,
                         verbose=True, sampling_efficiency='parameter',
-                        outputfiles_basename='outdir/pymultinest_label/',
+                        outputfiles_basename='outdir/pm_label/',
                         n_live_points=123, n_params=None,
                         n_clustering_params=None, wrapped_params=None,
                         multimodal=True, const_efficiency_mode=False,
diff --git a/tupak/core/sampler/pymultinest.py b/tupak/core/sampler/pymultinest.py
index 4ea5b0f2929e8868130e81f98e10746adc9d9d1d..025368318c4a78b316809b1d22c03348b876cb85 100644
--- a/tupak/core/sampler/pymultinest.py
+++ b/tupak/core/sampler/pymultinest.py
@@ -2,6 +2,7 @@ from __future__ import absolute_import
 
 from ..utils import check_directory_exists_and_if_not_mkdir
 from .base_sampler import NestedSampler
+from tupak.core.utils import logger
 
 
 class Pymultinest(NestedSampler):
@@ -48,12 +49,26 @@ class Pymultinest(NestedSampler):
                     kwargs['n_live_points'] = kwargs.pop(equiv)
 
     def _verify_kwargs_against_default_kwargs(self):
+        """
+        Test the length of the directory where multinest will write the output.
+
+        This is an issue with MultiNest that we can't solve here.
+        https://github.com/JohannesBuchner/PyMultiNest/issues/115
+        """
         if not self.kwargs['outputfiles_basename']:
-            self.kwargs['outputfiles_basename'] = self.outdir + '/pymultinest_{}/'.format(self.label)
+            self.kwargs['outputfiles_basename'] =\
+                '{}/pm_{}/'.format(self.outdir, self.label)
         if self.kwargs['outputfiles_basename'].endswith('/') is False:
             self.kwargs['outputfiles_basename'] = '{}/'.format(
                 self.kwargs['outputfiles_basename'])
-        check_directory_exists_and_if_not_mkdir(self.kwargs['outputfiles_basename'])
+        if len(self.kwargs['outputfiles_basename']) > (100 - 22):
+            logger.warning(
+                'The length of {} exceeds 78 characters. '
+                ' Post-processing will fail because the file names will be cut'
+                ' off. Please choose a shorter "outdir" or "label".'
+                .format(self.__kwargs['outputfiles_basename']))
+        check_directory_exists_and_if_not_mkdir(
+            self.kwargs['outputfiles_basename'])
         NestedSampler._verify_kwargs_against_default_kwargs(self)
 
     def run_sampler(self):