diff --git a/build-constraints.yaml b/build-constraints.yaml
index 39a9e668..41bc19b1 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3398,6 +3398,7 @@ packages:
         - pier-core < 0
         - pier < 0
         - haskeline
+        - ghc-source-gen
 
     "Christof Schramm <christof.schramm@campus.lmu.de>":
         - mnist-idx