diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 3798ace4..ddf161a6 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -9,14 +9,12 @@ on:
 env:
   GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
   MIX_ENV: test
-  LATEST_ELIXIR: "1.17"
-  LATEST_OTP: "27.0"
 
 jobs:
   lint:
     name: Lint
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
 
     strategy:
       fail-fast: true
@@ -28,8 +26,8 @@ jobs:
       - name: Install OTP and Elixir
         uses: erlef/setup-beam@v1
         with:
-          otp-version: "${{ env.LATEST_OTP }}"
-          elixir-version: "${{ env.LATEST_ELIXIR }}"
+          otp-version: "27.0"
+          elixir-version: "1.17.1"
 
       - name: Cache dependencies
         id: cache-deps
@@ -77,44 +75,30 @@ jobs:
 
   test:
     name: >-
-      Test (Elixir ${{ matrix.elixir }},
-      OTP ${{ matrix.otp }},
+      Test (Elixir ${{ matrix.runtime.elixir }},
+      OTP ${{ matrix.runtime.otp }} —
       C* ${{ matrix.server_versions.cassandra }},
-      Scylla ${{ matrix.server_versions.scylla }} (coverage: ${{ matrix.coverage }})
+      Scylla ${{ matrix.server_versions.scylla }})
 
-    runs-on: "${{ matrix.os }}"
+    runs-on: ubuntu-latest
 
     strategy:
       fail-fast: false
 
       matrix:
-        os:
-          - ubuntu-latest
-        otp:
-          - "25.3"
-        elixir:
-          - "1.16"
+        runtime:
+          # Oldest supported versions.
+          - otp: "25.3"
+            elixir: "1.15.4"
+          # Latest supported versions.
+          - otp: "27.0"
+            elixir: "1.17.1"
+
         server_versions:
           - cassandra: "3"
             scylla: "4.6.3"
-
-        include:
-          - os: ubuntu-latest
-            otp: "${{ github.env.LATEST_OTP }}"
-            elixir: "${{ github.env.LATEST_ELIXIR }}"
-            coverage: true
-            server_versions:
-              cassandra: "4.1"
-              scylla: "5.2"
-
-          # Oldest-supported Elixir and Erlang versions.
-          - os: ubuntu-latest
-            otp: "25.3"
-            elixir: "1.15.4"
-            coverage: false
-            server_versions:
-              cassandra: "4.1"
-              scylla: "5.2"
+          - cassandra: "4.1"
+            scylla: "5.2"
 
     env:
       CASSANDRA_VERSION: ${{ matrix.server_versions.cassandra }}
@@ -133,8 +117,8 @@ jobs:
       - name: Install OTP and Elixir
         uses: erlef/setup-beam@v1
         with:
-          otp-version: ${{ matrix.otp }}
-          elixir-version: ${{ matrix.elixir }}
+          otp-version: ${{ matrix.runtime.otp }}
+          elixir-version: ${{ matrix.runtime.elixir }}
 
       - name: Cache dependencies
         id: cache-deps
@@ -144,21 +128,16 @@ jobs:
             deps
             _build
           key: |
-            ${{ runner.os }}-mix-otp${{ matrix.otp }}-elixir${{ matrix.elixir }}-${{ hashFiles('**/mix.lock') }}
+            ${{ runner.os }}-mix-otp${{ matrix.runtime.otp }}-elixir${{ matrix.runtime.elixir }}-${{ hashFiles('**/mix.lock') }}
           restore-keys:
-            ${{ runner.os }}-mix-otp${{ matrix.otp }}-elixir${{ matrix.elixir }}-
+            ${{ runner.os }}-mix-otp${{ matrix.runtime.otp }}-elixir${{ matrix.runtime.elixir }}-
 
       - name: Install and compile dependencies
         if: steps.cache-deps.outputs.cache-hit != 'true'
-        run: mix do deps.get --only test
+        run: mix deps.get --only test
 
       # TODO: eventually figure out why we can't run encryption tests on CI.
-      - name: Run tests for Cassandra and Scylla (with coverage)
-        if: ${{ matrix.coverage }}
-        run: mix test.ci_with_coverage --exclude encryption --exclude toxiproxy
-
       - name: Run tests for Cassandra and Scylla (without coverage)
-        if: ${{ !matrix.coverage }}
         run: mix test.all --exclude encryption --exclude toxiproxy
 
       - name: Dump Docker logs on failure