diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index bcb310641d..7e1f1fd2bb 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -7,7 +7,7 @@ on:
     branches: [main]
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
@@ -16,11 +16,12 @@ jobs:
           node-version: 16
           cache: 'yarn'
       - run: yarn --frozen-lockfile
+      - run: yarn test:mocha
+      - run: yarn test:tsc
       - run: |
           echo ::add-matcher::.github/eslint.json
           yarn run eslint src test --format=compact
-      - run: yarn run prettier --check src test
-      - run: yarn test:mocha
+      - run: yarn test:prettier
       - run: yarn prepublishOnly
       - run: yarn docs:build
       - uses: actions/upload-artifact@v3
diff --git a/src/transforms/bin.d.ts b/src/transforms/bin.d.ts
index 61edab725f..b630278af9 100644
--- a/src/transforms/bin.d.ts
+++ b/src/transforms/bin.d.ts
@@ -164,7 +164,7 @@ export type BinYInputs<T> = Omit<T, "y"> & {y?: ChannelValueBinSpec} & BinOption
 export type BinInputs<T> = Omit<T, "x" | "y"> & {x?: ChannelValueBinSpec; y?: ChannelValueBinSpec} & BinOptions;
 
 /** Output channels (and options) for the bin transform. */
-export type BinOutputs = ChannelReducers<BinReducer> & GroupOutputOptions<BinReducer> & BinOptions;
+export type BinOutputs = ChannelReducers<BinReducer> | (GroupOutputOptions<BinReducer> & BinOptions);
 
 /**
  * Bins on the **x** channel; then subdivides bins on the first channel of
diff --git a/src/transforms/group.d.ts b/src/transforms/group.d.ts
index 24b422aa40..2ecbf22310 100644
--- a/src/transforms/group.d.ts
+++ b/src/transforms/group.d.ts
@@ -39,7 +39,7 @@ export interface GroupOutputOptions<T = Reducer> {
 }
 
 /** Output channels (and options) for the group transform. */
-export type GroupOutputs = ChannelReducers & GroupOutputOptions;
+export type GroupOutputs = ChannelReducers | GroupOutputOptions;
 
 /**
  * Groups on the first channel of **z**, **fill**, or **stroke**, if any, and