diff --git a/pycbc/__init__.py b/pycbc/__init__.py
index 3e8e1b9f28d..0d21a2b41d3 100644
--- a/pycbc/__init__.py
+++ b/pycbc/__init__.py
@@ -190,7 +190,8 @@ def makedir(path):
         if hasattr(multiprocessing, 'set_start_method'):
             multiprocessing.set_start_method('fork')
     elif multiprocessing.get_start_method() != 'fork':
-        raise ValueError("PyCBC requires the use of the 'fork' start method for multiprocessing")
+        warnings.warn("PyCBC requires the use of the 'fork' start method for multiprocessing, "
+                      "it is currently set to {}".format(multiprocessing.get_start_method()))
 else:
     HAVE_OMP = True