diff --git a/package.yaml b/package.yaml
index a3f244e..bb5bff5 100644
--- a/package.yaml
+++ b/package.yaml
@@ -22,7 +22,7 @@ description: Please see the README on GitHub at <https://github.com/gerdreiss/br
 dependencies:
   - base >= 4.7 && < 5
   - ansi-terminal
-  - brick
+  - brick <= 0.70.1
   - bytestring
   - cursor
   - microlens
@@ -32,7 +32,7 @@ dependencies:
   - text
   - time
   - typed-process
-  - vty
+  - vty <= 5.33
 
 ghc-options:
   - -Wall
diff --git a/stack.yaml b/stack.yaml
index 8dd6147..3f00ae3 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,5 +1,5 @@
-resolver:
-  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/19/31.yaml
+resolver: lts-20.1
 
-packages:
-  - .
+extra-deps:
+- brick-0.70.1@sha256:1c83fa171c70b084927a6961da6dfb0b586063b743dce405dec3ac92fa7edaf1,16337
+- vty-5.33@sha256:8da1652d64e24c9e011384628de340b2877f0148de7ef57baf66cd2e9a35c6c6,22294
\ No newline at end of file