diff --git a/optparse-helper.cabal b/optparse-helper.cabal
--- a/optparse-helper.cabal
+++ b/optparse-helper.cabal
@@ -1,5 +1,5 @@
 name:                optparse-helper
-version:             0.2.1.0
+version:             0.2.1.1
 synopsis:            Helper functions for optparse-applicative.
 description:
   The optparse-applicative package, as well as optparse-simple, has some
@@ -29,6 +29,7 @@
 extra-source-files:
   LICENSE
   README.md
+  stack.yaml
 
 library
   hs-source-dirs:      src
diff --git a/stack.yaml b/stack.yaml
new file mode 100644
--- /dev/null
+++ b/stack.yaml
@@ -0,0 +1,3 @@
+resolver: lts-6.0
+packages:
+  - '.'