diff --git a/.github/workflows/typecheck.yml b/.github/workflows/typecheck.yml
new file mode 100644
index 000000000..a1fdac0db
--- /dev/null
+++ b/.github/workflows/typecheck.yml
@@ -0,0 +1,55 @@
+name: Typecheck
+
+# Runs `yarn typecheck` from the repository root, which invokes
+# `tsc --noEmit` in every TypeScript workspace. Complements the existing
+# Lint and Test workflows (which do not run tsc) and catches type errors in
+# seconds instead of waiting for the slow Docker-image build in pr-gate.yml.
+#
+# The web workspace is excluded here because `tsc --noEmit` in `packages/web`
+# depends on `.next/types/**/*.ts` (declared in its tsconfig.json `include`)
+# being generated by `next build`. Web is already type-checked transitively
+# via the Docker build in pr-gate.yml. See issue #1437.
+
+on:
+  pull_request:
+    branches: ["main"]
+
+
+jobs:
+  typecheck:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          submodules: "true"
+
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+          cache: 'yarn'
+          cache-dependency-path: '**/yarn.lock'
+
+      - name: Install
+        run: yarn install --frozen-lockfile
+
+      # Build the type-source-of-truth workspaces first (schemas, db, shared,
+      # query-language) so their generated .d.ts files are fresh. Without
+      # this step, downstream workspaces see stale types and `tsc --noEmit`
+      # surfaces drift as errors.
+      - name: Build dependencies
+        run: yarn build:deps
+
+      # The db workspace's generated Prisma client must exist before its
+      # typecheck runs. Without this step, db's typecheck reports errors
+      # because the source-of-truth schema is newer than the generated client.
+      - name: Generate Prisma client
+        run: yarn workspace @sourcebot/db prisma:generate
+
+      # Excludes @sourcebot/web (see comment above). Runs tsc --noEmit in
+      # each remaining workspace in topological order.
+      - name: Typecheck
+        run: yarn workspaces foreach --all --topological --exclude @sourcebot/web run typecheck
diff --git a/package.json b/package.json
index ed846875f..b5d7fa757 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,7 @@
         "build": "cross-env SKIP_ENV_VALIDATION=1 yarn workspaces foreach --all --topological run build",
         "test": "yarn workspaces foreach --all --topological run test",
         "lint": "yarn workspaces foreach --all --topological run lint",
+        "typecheck": "yarn workspaces foreach --all --topological run typecheck",
         "dev": "concurrently --kill-others --names \"zoekt,worker,web,schemas\" 'yarn dev:zoekt' 'yarn dev:backend' 'yarn dev:web' 'yarn watch:schemas'",
         "with-env": "cross-env PATH=\"$PWD/bin:$PATH\" dotenv -e .env.development -c --",
         "dev:zoekt": "yarn with-env zoekt-webserver -index .sourcebot/index -rpc",
diff --git a/packages/backend/package.json b/packages/backend/package.json
index 7345ec2a2..b8739faba 100644
--- a/packages/backend/package.json
+++ b/packages/backend/package.json
@@ -8,6 +8,7 @@
         "dev:watch": "tsc-watch --preserveWatchOutput --onSuccess \"yarn dev\"",
         "dev": "node ./dist/index.js",
         "build": "tsc",
+        "typecheck": "tsc --noEmit",
         "test": "cross-env SKIP_ENV_VALIDATION=1 vitest --config ./vitest.config.ts"
     },
     "devDependencies": {
diff --git a/packages/db/package.json b/packages/db/package.json
index db623c5a2..ff728d659 100644
--- a/packages/db/package.json
+++ b/packages/db/package.json
@@ -5,6 +5,7 @@
     "private": true,
     "scripts": {
         "build": "yarn prisma:generate && tsc",
+        "typecheck": "tsc --noEmit",
         "postinstall": "yarn build",
         "prisma:generate": "prisma generate",
         "prisma:generate:watch": "prisma generate --watch",
diff --git a/packages/schemas/package.json b/packages/schemas/package.json
index 3719a6da5..79dcae370 100644
--- a/packages/schemas/package.json
+++ b/packages/schemas/package.json
@@ -4,6 +4,7 @@
     "private": true,
     "scripts": {
         "build": "yarn generate && tsc",
+        "typecheck": "tsc --noEmit",
         "generate": "tsx tools/generate.ts",
         "watch": "nodemon --watch ../../schemas -e json -x 'yarn build'",
         "postinstall": "yarn build"
diff --git a/packages/shared/package.json b/packages/shared/package.json
index 2a16111ff..7c4b4019e 100644
--- a/packages/shared/package.json
+++ b/packages/shared/package.json
@@ -5,6 +5,7 @@
     "private": true,
     "scripts": {
         "build": "tsc",
+        "typecheck": "tsc --noEmit",
         "build:watch": "tsc-watch --preserveWatchOutput",
         "postinstall": "yarn build",
         "test": "vitest --config ./vitest.config.ts",
diff --git a/packages/web/package.json b/packages/web/package.json
index 0f06c0d58..01bc5bd2c 100644
--- a/packages/web/package.json
+++ b/packages/web/package.json
@@ -7,6 +7,7 @@
     "build": "cross-env SKIP_ENV_VALIDATION=1 next build",
     "start": "next start",
     "lint": "cross-env SKIP_ENV_VALIDATION=1 eslint .",
+    "typecheck": "tsc --noEmit",
     "test": "cross-env SKIP_ENV_VALIDATION=1 vitest",
     "openapi:generate": "tsx tools/generateOpenApi.ts",
     "generate:protos": "proto-loader-gen-types --includeComments --longs=Number --enums=String --defaults --oneofs --grpcLib=@grpc/grpc-js --keepCase --includeDirs=../../vendor/zoekt/grpc/protos --outDir=src/proto zoekt/webserver/v1/webserver.proto zoekt/webserver/v1/query.proto",