diff --git a/stack9.4.yaml b/stack9.4.yaml
index e6850f7e8..63f490401 100644
--- a/stack9.4.yaml
+++ b/stack9.4.yaml
@@ -1,6 +1,6 @@
 # stack build plan using GHC 9.4.7
 
-resolver: lts-21.9
+resolver: lts-21.16
 
 packages:
 - hledger-lib