diff --git a/deb/stack.yaml b/deb/stack.yaml
index ef6a159ef..f714fe3e2 100644
--- a/deb/stack.yaml
+++ b/deb/stack.yaml
@@ -17,4 +17,6 @@ packages:
 extra-deps:
 - 'cmark-0.5.0'
 - 'pandoc-types-1.16.0.1'
-resolver: lts-3.20
+# Use older aeson to avoid excessive memory use in compilation:
+- 'aeson-0.8.0.2
+resolver: lts-4.0