diff --git a/setup.py b/setup.py
index 56de098..20ae061 100755
--- a/setup.py
+++ b/setup.py
@@ -39,6 +39,7 @@ def findsome(subdir, extensions):
     'core': [
         'datalad>=0.14.0',
         'scrapy>=1.1.0',  # versioning is primarily for python3 support
+        'boto',  # used directly by datalad_crawler/nodes/s3.py
     ],
     'devel-docs': [
         # Documentation