diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 9ab46d89..fbd9fdfc 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -7,7 +7,7 @@ on:
     - master
   workflow_dispatch:
 
-# As of 6 May 2024, ubuntu-latest and windows-latest come with Stack 2.15.5.
+# As of 21 October 2024, ubuntu-latest and windows-latest come with Stack 3.1.1.
 # However, macos-13 and macos-latest do not come with Haskell tools.
 
 jobs:
@@ -21,16 +21,16 @@ jobs:
         - ubuntu-latest
         snapshot:
         - stack-ghc-9.4.8.yaml
-        - stack-ghc-9.6.5.yaml
-        - stack-ghc-9.8.2.yaml
+        - stack-ghc-9.6.6.yaml
+        - stack-ghc-9.8.3.yaml
         include:
         - os: macos-13
-          snapshot: stack-ghc-9.8.2.yaml
+          snapshot: stack-ghc-9.8.3.yaml
         # macos-latest provides macOS/AArch64 (M1)
         - os: macos-latest
-          snapshot: stack-ghc-9.8.2.yaml
+          snapshot: stack-ghc-9.8.3.yaml
         - os: windows-latest
-          snapshot: stack-ghc-9.8.2.yaml
+          snapshot: stack-ghc-9.8.3.yaml
     steps:
     - name: Clone project
       uses: actions/checkout@v4
@@ -55,7 +55,7 @@ jobs:
 
         if [[ "${{ matrix.os }}" == "macos-13" || "${{ matrix.os }}" == "macos-latest" ]]
         then
-          # macos-13 and macos-latest do not include Haskell tools as at 2024-05-06.
+          # macos-13 and macos-latest do not include Haskell tools as at 2024-10-21.
           curl -sSL https://get.haskellstack.org/ | sh
         fi
 
@@ -70,7 +70,7 @@ jobs:
         - ubuntu-latest
         - windows-latest
         snapshot:
-        - stack-ghc-9.8.2.yaml
+        - stack-ghc-9.8.3.yaml
     steps:
     - name: Clone project
       uses: actions/checkout@v4
diff --git a/stack-ghc-9.6.5.yaml b/stack-ghc-9.6.5.yaml
deleted file mode 100644
index 00e8e5fb..00000000
--- a/stack-ghc-9.6.5.yaml
+++ /dev/null
@@ -1,2 +0,0 @@
-# Snapshot specification for GHC 9.6.5.
-snapshot: lts-22.21 # GHC 9.6.5
diff --git a/stack-ghc-9.6.6.yaml b/stack-ghc-9.6.6.yaml
new file mode 100644
index 00000000..e34aa8dc
--- /dev/null
+++ b/stack-ghc-9.6.6.yaml
@@ -0,0 +1,2 @@
+# Snapshot specification for GHC 9.6.6.
+snapshot: lts-22.39 # GHC 9.6.6
diff --git a/stack-ghc-9.8.2.yaml b/stack-ghc-9.8.2.yaml
deleted file mode 100644
index 54416d57..00000000
--- a/stack-ghc-9.8.2.yaml
+++ /dev/null
@@ -1,2 +0,0 @@
-# Snapshot specification for GHC 9.8.2.
-snapshot: nightly-2024-05-06 # GHC 9.8.2
diff --git a/stack-ghc-9.8.3.yaml b/stack-ghc-9.8.3.yaml
new file mode 100644
index 00000000..409f2d6c
--- /dev/null
+++ b/stack-ghc-9.8.3.yaml
@@ -0,0 +1,3 @@
+# Snapshot specification for GHC 9.8.3.
+snapshot: nightly-2024-10-21 # GHC 9.8.2
+compiler: ghc-9.8.3
diff --git a/stack.yaml b/stack.yaml
index 16075296..28cc40e9 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1 +1 @@
-snapshot: stack-ghc-9.6.5.yaml
+snapshot: stack-ghc-9.6.6.yaml