diff --git a/python/build/libs.py b/python/build/libs.py
index 526abbf64..cd3592578 100644
--- a/python/build/libs.py
+++ b/python/build/libs.py
@@ -19,9 +19,9 @@ libsamplerate = CmakeProject(
 )
 
 zlib = ZlibProject(
-    ('http://zlib.net/zlib-1.3.tar.xz',
-     'https://github.com/madler/zlib/releases/download/v1.3/zlib-1.3.tar.xz'),
-    '8a9ba2898e1d0d774eca6ba5b4627a11e5588ba85c8851336eb38de4683050a7',
+    ('http://zlib.net/zlib-1.3.1.tar.xz',
+     'https://github.com/madler/zlib/releases/download/v1.3.1/zlib-1.3.1.tar.xz'),
+    '38ef96b8dfe510d42707d9c781877914792541133e1870841463bfa73f883e32',
     'lib/libz.a',
 )