diff --git a/.github/workflows/workstation-mac-defaults-validation.yml b/.github/workflows/workstation-mac-defaults-validation.yml
new file mode 100644
index 0000000..768ccab
--- /dev/null
+++ b/.github/workflows/workstation-mac-defaults-validation.yml
@@ -0,0 +1,69 @@
+name: workstation-mac-defaults-validation
+
+on:
+  pull_request:
+    paths:
+      - 'profiles/linux-dev/workstation-v0/bin/check-mac-defaults.sh'
+      - 'profiles/linux-dev/workstation-v0/gnome/mac-defaults.sh'
+      - 'profiles/linux-dev/workstation-v0/gnome/README.md'
+      - '.github/workflows/workstation-mac-defaults-validation.yml'
+  push:
+    branches:
+      - main
+    paths:
+      - 'profiles/linux-dev/workstation-v0/bin/check-mac-defaults.sh'
+      - 'profiles/linux-dev/workstation-v0/gnome/mac-defaults.sh'
+      - 'profiles/linux-dev/workstation-v0/gnome/README.md'
+      - '.github/workflows/workstation-mac-defaults-validation.yml'
+
+jobs:
+  mac-defaults-smoke:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Syntax check mac-defaults scripts
+        run: |
+          set -euo pipefail
+          bash -n profiles/linux-dev/workstation-v0/gnome/mac-defaults.sh
+          bash -n profiles/linux-dev/workstation-v0/bin/check-mac-defaults.sh
+
+      - name: "Smoke: helper emits required keys"
+        run: |
+          set -euo pipefail
+          helper='profiles/linux-dev/workstation-v0/bin/check-mac-defaults.sh'
+          out=$(bash "$helper")
+          grep -F 'mac_defaults_script=present' <<<"$out" >/dev/null
+          grep -F 'hot_corners_disabled='       <<<"$out" >/dev/null
+          grep -F 'clock_format_12h='           <<<"$out" >/dev/null
+          grep -F 'locate_pointer_enabled='     <<<"$out" >/dev/null
+          grep -F 'nautilus_double_click='      <<<"$out" >/dev/null
+          grep -F 'dock_favorites_seed='        <<<"$out" >/dev/null
+          grep -F 'files_binding_super_e='      <<<"$out" >/dev/null
+          grep -F 'terminal_binding_super_ret=' <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_3='       <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_4='       <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_5='       <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_6='       <<<"$out" >/dev/null
+          grep -F 'mac_defaults_ok='            <<<"$out" >/dev/null
+
+      - name: "Smoke: helper detects all required settings as present"
+        run: |
+          set -euo pipefail
+          helper='profiles/linux-dev/workstation-v0/bin/check-mac-defaults.sh'
+          out=$(bash "$helper")
+          grep -F 'hot_corners_disabled=present'       <<<"$out" >/dev/null
+          grep -F 'clock_format_12h=present'           <<<"$out" >/dev/null
+          grep -F 'locate_pointer_enabled=present'     <<<"$out" >/dev/null
+          grep -F 'nautilus_double_click=present'      <<<"$out" >/dev/null
+          grep -F 'dock_favorites_seed=present'        <<<"$out" >/dev/null
+          grep -F 'files_binding_super_e=present'      <<<"$out" >/dev/null
+          grep -F 'terminal_binding_super_ret=present' <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_3=present'       <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_4=present'       <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_5=present'       <<<"$out" >/dev/null
+          grep -F 'screenshot_binding_6=present'       <<<"$out" >/dev/null
+          grep -F 'mac_defaults_ok=yes'                <<<"$out" >/dev/null
diff --git a/profiles/linux-dev/workstation-v0/gnome/README.md b/profiles/linux-dev/workstation-v0/gnome/README.md
index fdb5ec6..beec7ed 100644
--- a/profiles/linux-dev/workstation-v0/gnome/README.md
+++ b/profiles/linux-dev/workstation-v0/gnome/README.md
@@ -96,6 +96,32 @@ The workstation keeps keyboard remapping explicit and policy-gated:
 - Kinto remains an explicit compatibility lane for X11/xkeysnail-style workflows and is not auto-installed in the Wayland-first profile.
 - `check-keyboard-policy.sh` emits key=value status for CI and future doctor/status integration.
 
+## Mac-defaults validation
+
+The mac-like GNOME defaults pack can be inspected without changing system state:
+
+```bash
+./profiles/linux-dev/workstation-v0/bin/check-mac-defaults.sh
+```
+
+The helper emits key=value output for:
+
+- `mac_defaults_script`
+- `hot_corners_disabled`
+- `clock_format_12h`
+- `locate_pointer_enabled`
+- `nautilus_double_click`
+- `dock_favorites_seed`
+- `files_binding_super_e`
+- `terminal_binding_super_ret`
+- `screenshot_binding_3`, `screenshot_binding_4`, `screenshot_binding_5`, `screenshot_binding_6`
+- `mac_defaults_ok`
+
+It is read-only and does not require a GNOME session. It verifies that
+`mac-defaults.sh` records the intended desktop behavior slice by inspecting
+the script source. The check is wired into the
+`workstation-mac-defaults-validation` CI workflow.
+
 ## Dock/extension validation
 
 The dock and extension lane can be inspected without changing system state: