diff --git a/.gitignore b/.gitignore
index de2338f..46ee412 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,4 @@ cabal.project.local
 cabal.project.local~
 .HTF/
 .ghc.environment.*
+stack.yaml.lock
diff --git a/stack.yaml b/stack.yaml
index 9b0e238..ea112c3 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,3 +1,3 @@
-resolver: lts-14.4
+resolver: ghc-8.10.7
 packages:
 - .