diff --git a/.travis.yml b/.travis.yml
index b87da3f4..7c209ff1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -234,7 +234,7 @@ matrix:
               stack exec -- ihaskell install --stack
               test/acceptance.nbconvert.sh stack exec -- jupyter nbconvert
           fi
-    - env: DISPLAY=false   USE_STACK_YAML="stack.yaml"     # GHC 8.6.3
+    - env: DISPLAY=false   USE_STACK_YAML="stack.yaml"     # GHC 8.6.5
       language: python
       dist: xenial
       # Test against different stack LTS versions.
diff --git a/stack.yaml b/stack.yaml
index df4db849..18925698 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,4 +1,4 @@
-resolver: lts-13.26
+resolver: lts-14.7
 
 flags: {}
 packages: