diff --git a/.travis.yml b/.travis.yml
index 3922a7b..5076cd3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,7 @@ language: haskell
 sudo: required
 
 env:
-  - GHCVER=8.0.2 CABALVER=1.24 HAPPYVER=1.19.5 LD_LIBRARY_PATH=/usr/local/lib
+  - GHCVER=8.4.3 CABALVER=2.2.0.1 HAPPYVER=1.19.9 LD_LIBRARY_PATH=/usr/local/lib
 
 before_install:
   - cd ..
diff --git a/stack.yaml b/stack.yaml
index 14369dc..2099bf7 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,2 +1,2 @@
-resolver: lts-7.18
+resolver: lts-12.4
 system-ghc: true