diff --git a/build-constraints.yaml b/build-constraints.yaml
index 13beb08a..c03dac50 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -668,7 +668,8 @@ packages:
         - uri-encode
 
     "Simon Michael <simon@joyful.com> @simonmichael":
-        - darcs
+        # 2.12.1 testsuite http://bugs.darcs.net/issue2507
+        #- darcs
         - hledger
         - hledger-lib
         # - hledger-ui