diff --git a/stack.yaml b/stack.yaml
index 0c38ea5..c69d8cf 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,11 +1,8 @@
-resolver: 'lts-18.21'
+resolver: 'lts-19.17'
 
 packages:
 - '.'
 
-extra-deps:
-- 'optparse-applicative-0.16.1.0'
-
 nix:
   packages:
   - 'utillinux'  # For `rev`.
diff --git a/stack.yaml.lock b/stack.yaml.lock
index a4ab636..9648c3f 100644
--- a/stack.yaml.lock
+++ b/stack.yaml.lock
@@ -3,17 +3,10 @@
 # For more information, please see the documentation at:
 #   https://docs.haskellstack.org/en/stable/lock_files
 
-packages:
-- completed:
-    hackage: optparse-applicative-0.16.1.0@sha256:d410cc76e288b93d4ee7e06addc0381a7eaea43bcee0c3ced03f05cadec2f2fc,4836
-    pantry-tree:
-      size: 2979
-      sha256: bfff15197c553035578163cd3da352bcddcf0f11f57ae40ead22ef6dd120c40c
-  original:
-    hackage: optparse-applicative-0.16.1.0
+packages: []
 snapshots:
 - completed:
-    size: 586110
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/21.yaml
-    sha256: ce4fb8d44f3c6c6032060a02e0ebb1bd29937c9a70101c1517b92a87d9515160
-  original: lts-18.21
+    size: 619161
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/19/17.yaml
+    sha256: 7f47507fd037228a8d23cf830f5844e1f006221acebdd7cb49f2f5fb561e0546
+  original: lts-19.17