diff --git a/.circleci/config.yml b/.circleci/config.yml
index 386e1cc..48bbc7e 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -37,12 +37,14 @@ env: &env
       #STACKVER: "1.6.5"
       #STACK_UPGRADE: "y"
       #RESOLVER: "lts-12"
+      STACK_YAML: "stack.yaml"
 
       # ------------------------------------------------------------------------
       # cabal options
       # ------------------------------------------------------------------------
       CABAL_CHECK_RELAX: "y"
       CABAL_HACKAGE_MIRROR: "hackage.haskell.org:http://hackage.fpcomplete.com"
+      CABAL_PROJECT: "cabal.project"
 
       # ------------------------------------------------------------------------
       # Where to find the required tools
diff --git a/.github/workflows/packcheck.yml b/.github/workflows/packcheck.yml
index fa9f5f3..74f4c44 100644
--- a/.github/workflows/packcheck.yml
+++ b/.github/workflows/packcheck.yml
@@ -27,7 +27,6 @@ jobs:
       ${{ matrix.command }}
       ${{ matrix.runner }}
       ${{ matrix.ghc_version }}
-      ${{ matrix.stack_resolver }}
     env:
       # ------------------------------------------------------------------------
       # Common options
@@ -50,7 +49,7 @@ jobs:
       # Selecting tool versions
       # ------------------------------------------------------------------------
       GHCVER: ${{ matrix.ghc_version }}
-      RESOLVER: ${{ matrix.stack_resolver }}
+      # RESOLVER: ${{ matrix.stack_resolver }}
 
       # ------------------------------------------------------------------------
       # stack options
@@ -60,12 +59,14 @@ jobs:
       # version.
       #STACKVER: "1.6.5"
       #STACK_UPGRADE: "y"
+      STACK_YAML: "stack.yaml"
 
       # ------------------------------------------------------------------------
       # cabal options
       # ------------------------------------------------------------------------
       CABAL_CHECK_RELAX: y
       CABAL_HACKAGE_MIRROR: "hackage.haskell.org:http://hackage.fpcomplete.com"
+      CABAL_PROJECT: "cabal.project"
 
       # ------------------------------------------------------------------------
       # Where to find the required tools
@@ -120,7 +121,6 @@ jobs:
         include:
           # Additional ci matrix elements
           # - name: ci
-          #   stack_resolver: lts-18.2
           #   command: stack
           #   runner: ubuntu-latest
 
@@ -155,7 +155,7 @@ jobs:
           ~/.ghc
           ~/.local
           ~/.stack
-        key: ${{ matrix.ghc_version }}-${{ matrix.stack_resolver }}-${{ matrix.runner }}
+        key: ${{ matrix.command }}-${{ matrix.ghc_version }}-${{ matrix.runner }}
 
     - name: Download packcheck
       run: |
diff --git a/.travis.yml b/.travis.yml
index 3deecba..3e37851 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -34,12 +34,14 @@ env:
   # version.
   #- STACKVER="1.6.5"
   - STACK_UPGRADE="y"
+  - STACK_YAML="stack.yaml"
 
   # ------------------------------------------------------------------------
   # cabal options
   # ------------------------------------------------------------------------
   - CABAL_CHECK_RELAX=y
   - CABAL_HACKAGE_MIRROR=hackage.haskell.org:http://hackage.fpcomplete.com
+  - CABAL_PROJECT="cabal.project"
 
   # ------------------------------------------------------------------------
   # Where to find the required tools
diff --git a/appveyor.yml b/appveyor.yml
index 28d2067..80d13dc 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -34,14 +34,16 @@ environment:
     # version.
     #STACKVER: "1.6.5"
     STACK_UPGRADE: "y"
-    RESOLVER: "lts-15"
+    # RESOLVER: "lts-15"
     STACK_ROOT: "c:\\sr"
+    STACK_YAML: "stack.yaml"
 
     # ------------------------------------------------------------------------
     # cabal options
     # ------------------------------------------------------------------------
     CABAL_CHECK_RELAX: "y"
     CABAL_HACKAGE_MIRROR: "hackage.haskell.org:http://hackage.fpcomplete.com"
+    CABAL_PROJECT: "cabal.project"
 
     # ------------------------------------------------------------------------
     # Where to find the required tools