diff --git a/contrib/python3-whitelist b/contrib/python3-whitelist
--- a/contrib/python3-whitelist
+++ b/contrib/python3-whitelist
@@ -185,6 +185,7 @@
 test-export.t
 test-extdata.t
 test-extdiff.t
+test-extension.t
 test-extensions-afterloaded.t
 test-extensions-wrapfunction.py
 test-extra-filelog-entry.t
diff --git a/tests/test-extension.t b/tests/test-extension.t
--- a/tests/test-extension.t
+++ b/tests/test-extension.t
@@ -531,6 +531,10 @@
 
 Examine whether sub-module is imported relatively as expected.
 
+#endif
+
+#if demandimport no-py3k
+
 See also issue5208 for detail about example case on Python 3.x.
 
   $ f -q $TESTTMP/extlibroot/lsub1/lsub2/notexist.py