diff --git a/postgresql.yaml b/postgresql.yaml
index a797e1a..460d99b 100644
--- a/postgresql.yaml
+++ b/postgresql.yaml
@@ -51,4 +51,6 @@ data:
       postgresql:
         buildorder: 2
         rationale: 'The API we want to provide.'
-        ref: f26
+        # This branch doesn't BR: systemtap(-devel) which pulls in loads of
+        # other junk
+        ref: private-f27-module