diff --git a/all_stack.sh b/all_stack.sh
index 83ba641b8..85fa99a43 100755
--- a/all_stack.sh
+++ b/all_stack.sh
@@ -92,3 +92,5 @@ stack build --resolver lts-12.16
 stack build --resolver lts-12.17
 stack build --resolver lts-12.18
 stack build --resolver lts-12.19
+stack build --resolver lts-12.20
+stack build --resolver lts-12.21