diff --git a/Lib/test/test_sysconfig.py b/Lib/test/test_sysconfig.py
index 3738914cf17de8..cc11eade2e3426 100644
--- a/Lib/test/test_sysconfig.py
+++ b/Lib/test/test_sysconfig.py
@@ -643,7 +643,8 @@ def test_sysconfigdata_json(self):
 
         system_config_vars = get_config_vars()
 
-        ignore_keys = set()
+        # Keys dependent on uncontrollable external context
+        ignore_keys = {'userbase'}
         # Keys dependent on Python being run outside the build directrory
         if sysconfig.is_python_build():
             ignore_keys |= {'srcdir'}
diff --git a/Misc/NEWS.d/next/Library/2024-12-18-15-51-09.gh-issue-128055.0c_Noq.rst b/Misc/NEWS.d/next/Library/2024-12-18-15-51-09.gh-issue-128055.0c_Noq.rst
new file mode 100644
index 00000000000000..4f7be59d5b63b4
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-12-18-15-51-09.gh-issue-128055.0c_Noq.rst
@@ -0,0 +1,2 @@
+Fix ``test.test_sysconfig.test_sysconfigdata_json`` when running outside
+the build directory (eg. after installing).