diff --git a/.github/workflows/checks.yaml b/.github/workflows/checks.yaml
index 9851aeb2..02b4e164 100644
--- a/.github/workflows/checks.yaml
+++ b/.github/workflows/checks.yaml
@@ -75,20 +75,21 @@ jobs:
 
       - run: npm ci
       # prettier-ignore
-      - run: npm install eslint@${{ matrix.eslint }} @types/eslint@${{ matrix.eslint }} @eslint/js@${{ matrix.eslint }} @typescript-eslint/parser@${{ matrix.typescript-eslint }} @typescript-eslint/eslint-plugin@${{ matrix.typescript-eslint }} --no-fund
-      - if: matrix.eslint == 8
-        run: npm i -D @types/eslint__js@${{ matrix.eslint }}
-      - if: matrix.eslint != 8 # v9+ provides its own types
-        run: npm un @types/eslint @types/eslint__js
+      - run: tools/install-eslint-dependencies.sh ${{ matrix.eslint }} ${{ matrix.typescript-eslint }}
       - run: npm run lint
   test:
     permissions:
       contents: read # to fetch code (actions/checkout)
-    name: Test on ${{ matrix.os }} using Node.js LTS
+    name: Test on ${{ matrix.os }} with eslint v${{ matrix.eslint }}, @typescript-eslint v${{ matrix.typescript-eslint }}, and using Node.js LTS
     strategy:
       fail-fast: false
       matrix:
+        eslint: [8, 9]
+        typescript-eslint: [7, 8]
         os: [ubuntu-latest, macOS-latest]
+        exclude:
+          - eslint: 9
+            typescript-eslint: 7
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
@@ -100,17 +101,23 @@ jobs:
           cache: npm
 
       - run: npm ci
+      # prettier-ignore
+      - run: tools/install-eslint-dependencies.sh ${{ matrix.eslint }} ${{ matrix.typescript-eslint }}
       - run: npm run test
   typecheck:
     permissions:
       contents: read # to fetch code (actions/checkout)
     # prettier-ignore
-    name: Typecheck on ${{ matrix.os }} using Node.js LTS and ESLint v${{ matrix.eslint }} types
+    name: Typecheck on ${{ matrix.os }} with eslint v${{ matrix.eslint }}, @typescript-eslint v${{ matrix.typescript-eslint }}, and using Node.js LTS
     strategy:
       fail-fast: false
       matrix:
         eslint: [8, 9]
+        typescript-eslint: [7, 8]
         os: [ubuntu-latest, macOS-latest]
+        exclude:
+          - eslint: 9
+            typescript-eslint: 7
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
@@ -123,9 +130,5 @@ jobs:
 
       - run: npm ci
       # prettier-ignore
-      - run: npm i -D eslint@${{ matrix.eslint }} @types/eslint@${{ matrix.eslint }} @eslint/js@${{ matrix.eslint }}
-      - if: matrix.eslint == 8
-        run: npm i -D @types/eslint__js@${{ matrix.eslint }}
-      - if: matrix.eslint != 8 # v9+ provides its own types
-        run: npm un @types/eslint @types/eslint__js
+      - run: tools/install-eslint-dependencies.sh ${{ matrix.eslint }} ${{ matrix.typescript-eslint }}
       - run: npm run typecheck
diff --git a/tools/install-eslint-dependencies.sh b/tools/install-eslint-dependencies.sh
new file mode 100755
index 00000000..ab1a250f
--- /dev/null
+++ b/tools/install-eslint-dependencies.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+set -e
+
+esv=${1?'must be eslint major version'}
+tsv=${2?'must be typescript eslint major version'}
+
+npm install -D \
+  "eslint@$esv" \
+  "@types/eslint@$esv" \
+  "@eslint/js@$esv" \
+  "@typescript-eslint/parser@$tsv" \
+  "@typescript-eslint/eslint-plugin@$tsv"
+
+# ESLint v9+ ships with its own types
+if [ "$esv" -eq 8 ]; then
+  npm install -D "@types/eslint__js@$esv"
+else
+  npm uninstall -D @types/eslint @types/eslint__js
+fi
diff --git a/types.d.ts b/types.d.ts
index e2f940e1..2e402945 100644
--- a/types.d.ts
+++ b/types.d.ts
@@ -113,11 +113,20 @@ declare module '@typescript-eslint/eslint-plugin' {
   export = plugin;
 }
 
-// todo: doesn't get its own types until v8
+// todo: we need to specify our own types to ensure compatibility with both ESLint v8 and v9
 declare module '@typescript-eslint/parser' {
   import * as ESLint from 'eslint';
 
-  const parser: ESLint.Linter.ParserModule;
+  const parser: ESLint.ESLint.ObjectMetaProperties &
+    (
+      | {
+          parseForESLint(
+            text: string,
+            options?: unknown
+          ): ESLint.Linter.ESLintParseResult;
+        }
+      | { parse(text: string, options?: unknown): ESLint.AST.Program }
+    );
   export = parser;
 }