diff --git a/src/pynwb/validate.py b/src/pynwb/validate.py
index 646e8f4b8..bc2358b1a 100644
--- a/src/pynwb/validate.py
+++ b/src/pynwb/validate.py
@@ -7,7 +7,7 @@
 from hdmf.build import TypeMap as TypeMap
 from hdmf.backends.hdf5 import HDF5IO
 
-from pynwb import validate, available_namespaces, NWBHDF5IO
+from pynwb import validate, CORE_NAMESPACE, NWBHDF5IO
 from pynwb.spec import NWBDatasetSpec, NWBGroupSpec, NWBNamespace
 
 
@@ -75,7 +75,7 @@ def main():
                 specloc = "cached namespace information"
             else:
                 manager = None
-                namespaces = available_namespaces()
+                namespaces = [CORE_NAMESPACE]
                 specloc = "pynwb namespace information"
                 print("The file {} has no cached namespace information. "
                       "Falling back to {}.".format(path, specloc), file=sys.stderr)
@@ -92,7 +92,7 @@ def main():
             specloc = "--nspath namespace information"
         else:
             manager = None
-            namespaces = available_namespaces()
+            namespaces = [CORE_NAMESPACE]
             specloc = "pynwb namespace information"
 
         if args.ns: