diff --git a/pycbc/__init__.py b/pycbc/__init__.py
index d6db0026e0a..99f4cc6ef37 100644
--- a/pycbc/__init__.py
+++ b/pycbc/__init__.py
@@ -212,8 +212,13 @@ def makedir(path):
     # preserve common state information which we have relied on when using
     # multiprocessing based pools.
     import multiprocessing
-    if hasattr(multiprocessing, 'set_start_method'):
-        multiprocessing.set_start_method('fork')
+    if multiprocessing.get_start_method(allow_none=True) is None:
+        if hasattr(multiprocessing, 'set_start_method'):
+            multiprocessing.set_start_method('fork')
+    elif multiprocessing.get_start_method() != 'fork':
+        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