diff --git a/.github/workflows/oneclient_nightly.yml b/.github/workflows/oneclient_nightly.yml
index 2fcf0269..99275230 100644
--- a/.github/workflows/oneclient_nightly.yml
+++ b/.github/workflows/oneclient_nightly.yml
@@ -28,6 +28,7 @@ jobs:
             os_key: darwin
             arch: x86_64
             formats: app,dmg
+            macos_deployment_target: '10.14'
           - platform: ubuntu-22.04
             target: ''
             os_key: linux
@@ -43,6 +44,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: (macOS) Pin deployment target
+        if: matrix.macos_deployment_target != ''
+        shell: bash
+        run: echo "MACOSX_DEPLOYMENT_TARGET=${{ matrix.macos_deployment_target }}" >> "$GITHUB_ENV"
+
       - name: Setup Rust
         uses: ./.github/actions/setup-rust
         with:
@@ -74,6 +80,19 @@ jobs:
             cargo build --release --bin oneclient_app
           fi
 
+      - name: (macOS) Verify deployment target
+        if: matrix.macos_deployment_target != ''
+        shell: bash
+        run: |
+          set -euo pipefail
+          bin="target/${{ matrix.target }}/release/oneclient_app"
+          minos="$(vtool -show-build "$bin" | awk '/minos/ {print $2; exit}')"
+          echo "linked minos=$minos, declared minimum=${{ matrix.macos_deployment_target }}"
+          if [ "$(printf '%s\n%s\n' "$minos" "${{ matrix.macos_deployment_target }}" | sort -V | tail -n1)" != "${{ matrix.macos_deployment_target }}" ]; then
+            echo "::error::Binary requires macOS $minos but the bundle advertises ${{ matrix.macos_deployment_target }}."
+            exit 1
+          fi
+
       - name: Package (unsigned)
         shell: bash
         env:
diff --git a/.github/workflows/oneclient_release.yml b/.github/workflows/oneclient_release.yml
index 35a1857a..f67f51e9 100644
--- a/.github/workflows/oneclient_release.yml
+++ b/.github/workflows/oneclient_release.yml
@@ -61,6 +61,7 @@ jobs:
             os_key: darwin
             arch: x86_64
             formats: app,dmg
+            macos_deployment_target: '10.14'
           - platform: ubuntu-22.04
             target: ''
             os_key: linux
@@ -76,6 +77,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: (macOS) Pin deployment target
+        if: matrix.macos_deployment_target != ''
+        shell: bash
+        run: echo "MACOSX_DEPLOYMENT_TARGET=${{ matrix.macos_deployment_target }}" >> "$GITHUB_ENV"
+
       - name: Setup Rust
         uses: ./.github/actions/setup-rust
         with:
@@ -143,6 +149,19 @@ jobs:
             cargo build --release --bin oneclient_app
           fi
 
+      - name: (macOS) Verify deployment target
+        if: matrix.macos_deployment_target != ''
+        shell: bash
+        run: |
+          set -euo pipefail
+          bin="target/${{ matrix.target }}/release/oneclient_app"
+          minos="$(vtool -show-build "$bin" | awk '/minos/ {print $2; exit}')"
+          echo "linked minos=$minos, declared minimum=${{ matrix.macos_deployment_target }}"
+          if [ "$(printf '%s\n%s\n' "$minos" "${{ matrix.macos_deployment_target }}" | sort -V | tail -n1)" != "${{ matrix.macos_deployment_target }}" ]; then
+            echo "::error::Binary requires macOS $minos but the bundle advertises ${{ matrix.macos_deployment_target }}."
+            exit 1
+          fi
+
       - name: Package
         shell: bash
         env:
diff --git a/packages/oneclient_app/Cargo.toml b/packages/oneclient_app/Cargo.toml
index 3218cd8c..1f0d6793 100644
--- a/packages/oneclient_app/Cargo.toml
+++ b/packages/oneclient_app/Cargo.toml
@@ -69,7 +69,7 @@ icons = [
 ]
 
 [package.metadata.packager.macos]
-minimum-system-version = "10.15"
+minimum-system-version = "10.14"
 entitlements = "distribution/App.entitlements"
 info-plist-path = "distribution/Info.plist"