diff --git a/CHANGES b/CHANGES
index 16de1de524..7b6f8b1291 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4878.	[bug]		List 'ply' as a requirement for the 'isc' python
+			package. [RT #47065]
+
 4877.	[bug]		Address integer overflow when exponentially
 			backing off retry intervals. [RT #47041]
 
diff --git a/bin/python/setup.py b/bin/python/setup.py
index 8782402963..1084ed3870 100644
--- a/bin/python/setup.py
+++ b/bin/python/setup.py
@@ -14,4 +14,5 @@ setup(name='isc',
       author='Internet Systems Consortium, Inc',
       author_email='bind9-bugs@isc.org',
       license='ISC',
+      requires=['ply'],
       packages=['isc'])