diff --git a/python/sites/mach.txt b/python/sites/mach.txt
index d105723399..b10a7e42d7 100644
--- a/python/sites/mach.txt
+++ b/python/sites/mach.txt
@@ -143,4 +143,4 @@ pypi-optional:glean-sdk==52.7.0:telemetry will not be collected
 # We aren't (yet) able to pin packages in automation, so we have to
 # support down to the oldest locally-installed version (5.4.2).
 pypi-optional:psutil>=5.4.2,<=5.9.4:telemetry will be missing some data
-pypi-optional:zstandard>=0.11.1,<=0.19.0:zstd archives will not be possible to extract
+pypi-optional:zstandard>=0.11.1,<=0.21.0:zstd archives will not be possible to extract