diff --git a/changes/ticket40126 b/changes/ticket40126
new file mode 100644
index 0000000000..1f5806e6cb
--- /dev/null
+++ b/changes/ticket40126
@@ -0,0 +1,4 @@
+  o Testing (onion service v2):
+    - Fix another rendezvous cache unit test that was triggering an underflow on the
+      global rend cache allocation. Fixes bug 40126; bugfix on
+      0.2.8.1-alpha.
diff --git a/src/test/test_rendcache.c b/src/test/test_rendcache.c
index de8c0aef41..06167635c1 100644
--- a/src/test/test_rendcache.c
+++ b/src/test/test_rendcache.c
@@ -950,6 +950,7 @@ test_rend_cache_free_all(void *data)
   one->parsed = desc_one;
   desc_one->timestamp = time(NULL) + TIME_IN_THE_PAST;
   desc_one->pk = pk_generate(0);
+  rend_cache_increment_allocation(rend_cache_entry_allocation(one));
   strmap_set_lc(rend_cache, "foo1", one);
 
   rend_cache_free_all();