diff --git a/pyontutils/namespaces.py b/pyontutils/namespaces.py
index <HASH>..<HASH> 100644
--- a/pyontutils/namespaces.py
+++ b/pyontutils/namespaces.py
@@ -187,7 +187,6 @@ def _loadPrefixes():
         'NLXWIKI':'http://neurolex.org/wiki/',
         # FIXME a thought: was # intentionally used to increase user privacy? or is this just happenstance?
         'nsu':'http://www.FIXME.org/nsupper#',
-        'core1':'http://purl.obolibrary.org/obo/core#', # common enough prefix
         'oboInOwl':'http://www.geneontology.org/formats/oboInOwl#',
         'ro':'http://www.obofoundry.org/ro/ro.owl#',
removed core1 because it accually wasn't that common