diff --git a/build/pkgs/packaging/install-requires.txt b/build/pkgs/packaging/install-requires.txt
index 564ba90b0a5..cb98c369e84 100644
--- a/build/pkgs/packaging/install-requires.txt
+++ b/build/pkgs/packaging/install-requires.txt
@@ -1 +1,2 @@
 packaging >=18.0
+# Trac #30975: packaging 20.5 is known to work but we have to silence "DeprecationWarning: Creating a LegacyVersion"