diff --git a/.github/workflows/studio-mac-update-smoke.yml b/.github/workflows/studio-mac-update-smoke.yml
index 07d26b9ab3..cfa192b470 100644
--- a/.github/workflows/studio-mac-update-smoke.yml
+++ b/.github/workflows/studio-mac-update-smoke.yml
@@ -21,6 +21,7 @@ on:
   pull_request:
     paths:
       - 'install.sh'
+      - 'uninstall.sh'
       - 'studio/setup.sh'
       - 'studio/install_python_stack.py'
       - 'studio/install_llama_prebuilt.py'
@@ -137,6 +138,38 @@ jobs:
           kill "$PID" 2>/dev/null || true
           echo "post-update Studio /api/health OK"
 
+      - name: Uninstall and verify clean
+        # Round-trip through uninstall.sh on real macOS. As a side effect
+        # this exercises the macOS-only .app bundle + Launch Services
+        # removal path (~/Applications/Unsloth Studio.app, lsregister -u)
+        # which is not testable from a Linux runner. Skips gracefully if
+        # uninstall.sh has not landed yet (lets this workflow merge
+        # before #5497).
+        run: |
+          set -o pipefail
+          if [ ! -f uninstall.sh ]; then
+            echo "uninstall.sh not present in this tree; skipping round-trip"
+            : > logs/uninstall.log
+            exit 0
+          fi
+          sh uninstall.sh 2>&1 | tee logs/uninstall.log
+          leak=0
+          for p in \
+            "$HOME/.unsloth/studio" \
+            "$HOME/.local/share/unsloth" \
+            "$HOME/Applications/Unsloth Studio.app" \
+            "$HOME/Desktop/Unsloth Studio.app" \
+            "$HOME/.local/bin/unsloth"; do
+            if [ -e "$p" ] || [ -L "$p" ]; then
+              echo "::error::leak: $p"
+              leak=$((leak + 1))
+            fi
+          done
+          [ "$leak" -eq 0 ] || exit 1
+          sh uninstall.sh 2>&1 | tail -5
+          sh uninstall.sh 2>&1 | tail -5
+          echo "PASS: mac install -> update -> uninstall round-trip clean"
+
       - name: Upload update logs
         if: always()
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
@@ -147,4 +180,5 @@ jobs:
             logs/update.log
             logs/update2.log
             logs/studio.log
+            logs/uninstall.log
           retention-days: 7
diff --git a/.github/workflows/studio-update-smoke.yml b/.github/workflows/studio-update-smoke.yml
index 1c353e933a..b28e2bf0bd 100644
--- a/.github/workflows/studio-update-smoke.yml
+++ b/.github/workflows/studio-update-smoke.yml
@@ -15,6 +15,7 @@ on:
   pull_request:
     paths:
       - 'install.sh'
+      - 'uninstall.sh'
       - 'studio/setup.sh'
       - 'studio/install_python_stack.py'
       - 'studio/install_llama_prebuilt.py'
@@ -139,9 +140,44 @@ jobs:
           kill "$PID" 2>/dev/null || true
           echo "post-update Studio /api/health OK"
 
+      - name: Uninstall and verify clean
+        # Round-trip the installer through uninstall.sh: confirms the
+        # uninstaller actually finds and removes everything install.sh +
+        # update wrote. Safety-guard scenarios (refuse-$HOME etc.) belong
+        # in a separate fast smoke job; this is the happy-path cleanup
+        # assertion that catches regressions where install.sh starts
+        # writing to a new location and uninstall.sh hasn't caught up.
+        # Skips gracefully if uninstall.sh has not landed yet (lets this
+        # workflow merge before #5497).
+        run: |
+          set -o pipefail
+          if [ ! -f uninstall.sh ]; then
+            echo "uninstall.sh not present in this tree; skipping round-trip"
+            : > logs/uninstall.log
+            exit 0
+          fi
+          sh uninstall.sh 2>&1 | tee logs/uninstall.log
+          leak=0
+          for p in \
+            "$HOME/.unsloth/studio" \
+            "$HOME/.local/share/unsloth" \
+            "$HOME/Desktop/Unsloth Studio.desktop" \
+            "$HOME/.local/bin/unsloth"; do
+            if [ -e "$p" ] || [ -L "$p" ]; then
+              echo "::error::leak: $p"
+              ls -la "$p" 2>&1 | head -3
+              leak=$((leak + 1))
+            fi
+          done
+          [ "$leak" -eq 0 ] || exit 1
+          # Idempotent: re-runs exit 0 on an empty $HOME.
+          sh uninstall.sh 2>&1 | tail -5
+          sh uninstall.sh 2>&1 | tail -5
+          echo "PASS: install -> update -> uninstall round-trip clean"
+
       - name: Upload update logs
         # Always upload so a green run still leaves the install + two
-        # update logs reviewable.
+        # update logs + uninstall log reviewable.
         if: always()
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
         with:
@@ -151,4 +187,5 @@ jobs:
             logs/update.log
             logs/update2.log
             logs/studio.log
+            logs/uninstall.log
           retention-days: 7
diff --git a/.github/workflows/studio-windows-update-smoke.yml b/.github/workflows/studio-windows-update-smoke.yml
index 157874d404..b412d60921 100644
--- a/.github/workflows/studio-windows-update-smoke.yml
+++ b/.github/workflows/studio-windows-update-smoke.yml
@@ -23,6 +23,7 @@ on:
   pull_request:
     paths:
       - 'install.ps1'
+      - 'uninstall.ps1'
       - 'studio/setup.ps1'
       - 'studio/setup.bat'
       - 'studio/install_python_stack.py'
@@ -266,6 +267,39 @@ jobs:
           kill "$PID" 2>/dev/null || true
           echo "post-update Studio /api/health OK"
 
+      - name: Uninstall and verify clean
+        # Round-trip through uninstall.ps1 against the default install
+        # tree at %USERPROFILE%\.unsloth\studio. Catches regressions
+        # where install.ps1 starts writing under a new key (registry,
+        # Start Menu, %APPDATA%) and uninstall.ps1 has not been updated
+        # to match. Skips gracefully if uninstall.ps1 has not landed yet
+        # (lets this workflow merge before #5513).
+        shell: pwsh
+        run: |
+          New-Item -ItemType Directory -Force -Path logs | Out-Null
+          if (-not (Test-Path "$PWD\uninstall.ps1")) {
+            Write-Host "uninstall.ps1 not present in this tree; skipping round-trip"
+            "" | Set-Content logs/uninstall.log
+            exit 0
+          }
+          pwsh -NoProfile -File "$PWD\uninstall.ps1" *>&1 | Tee-Object -FilePath logs/uninstall.log
+          $leak = 0
+          foreach ($p in @(
+            "$env:USERPROFILE\.unsloth\studio",
+            "$env:USERPROFILE\.unsloth\studio\unsloth_studio",
+            "$env:USERPROFILE\.unsloth\studio\bin\unsloth.exe"
+          )) {
+            if (Test-Path -LiteralPath $p) {
+              Write-Host "::error::leak: $p"
+              $leak++
+            }
+          }
+          if ($leak -gt 0) { exit 1 }
+          # Idempotency.
+          pwsh -NoProfile -File "$PWD\uninstall.ps1" *>&1 | Select-Object -Last 5
+          pwsh -NoProfile -File "$PWD\uninstall.ps1" *>&1 | Select-Object -Last 5
+          Write-Host "PASS: windows install -> update -> uninstall round-trip clean"
+
       - name: Upload update logs
         if: always()
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
@@ -276,4 +310,5 @@ jobs:
             logs/update.log
             logs/update2.log
             logs/studio.log
+            logs/uninstall.log
           retention-days: 7