diff --git a/roles/xmpp_server/molecule/default/molecule.yml b/roles/xmpp_server/molecule/default/molecule.yml
index b800f059efef57644141854c4884723ffd9a4093..058d724fa79b3d451f36d54f211fe8beaf44eea2 100644
--- a/roles/xmpp_server/molecule/default/molecule.yml
+++ b/roles/xmpp_server/molecule/default/molecule.yml
@@ -38,7 +38,11 @@ platforms:
     groups:
       - clients
       - bullseye
-    box: debian/bullseye64
+    # Use Bookworm client box for testing Bullseye servers to avoid
+    # duplication of test code in test_client.py due to missing
+    # functional build of go-sendxmpp for the Bullseye release (glibc
+    # mismatch in prebuilt package).
+    box: debian/bookworm64
     memory: 256
     cpus: 1
     provider_raw_config_args: