diff --git a/stack.yaml b/stack.yaml
index 8d66faa1f..68c92b9bb 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,6 +1,6 @@
-# stack build plan using GHC 9.4.6
+# stack build plan using GHC 9.6.2
 
-resolver: lts-21.9
+resolver: nightly-2023-09-09
 
 packages:
 - hledger-lib
@@ -8,9 +8,7 @@ packages:
 - hledger-ui
 - hledger-web
 
-#extra-deps:
-
-#allow-newer: true
+# extra-deps:
 
 nix:
   pure: false
diff --git a/stack9.4.yaml b/stack9.4.yaml
new file mode 100644
index 000000000..e6850f7e8
--- /dev/null
+++ b/stack9.4.yaml
@@ -0,0 +1,33 @@
+# stack build plan using GHC 9.4.7
+
+resolver: lts-21.9
+
+packages:
+- hledger-lib
+- hledger
+- hledger-ui
+- hledger-web
+
+# extra-deps:
+
+nix:
+  pure: false
+  packages: [perl gmp ncurses zlib]
+
+# ghc-options:
+#   "$locals": -fplugin Debug.Breakpoint
+
+# # for precise profiling, per https://www.tweag.io/posts/2020-01-30-haskell-profiling.html:
+# # apply-ghc-options: everything
+# # rebuild-ghc-options: true
+# # stack build --profile --ghc-options="-fno-prof-auto"
+
+# # tell GHC to write hie files, eg for weeder. Rumoured to be slow.
+# # ghc-options:
+# #   "$locals": -fwrite-ide-info
+
+# # ghc-options:
+# #   "$locals": -ddump-timings
+# #  "$targets": -Werror
+# #  "$everything": -O2
+# #  some-package: -DSOME_CPP_FLAG