diff --git a/.github/workflows/phpunit-feature.yml b/.github/workflows/phpunit-feature.yml
index 7ceeb6627..75a665f54 100644
--- a/.github/workflows/phpunit-feature.yml
+++ b/.github/workflows/phpunit-feature.yml
@@ -182,6 +182,7 @@ jobs:
         run: echo "key=server-php-tools-v2-${{ runner.os }}-${{ runner.arch }}-$(date -u +%Y%m%d)-${{ hashFiles('Dockerfile', 'Dockerfile.dockerignore', '.dockerignore', 'docker/**') }}" >> "$GITHUB_OUTPUT"
 
       - name: Restore the source-free PHP tool images
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
         id: php_tools_cache
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
diff --git a/.github/workflows/server-parity.yml b/.github/workflows/server-parity.yml
index 54eaaa326..27703d428 100644
--- a/.github/workflows/server-parity.yml
+++ b/.github/workflows/server-parity.yml
@@ -203,6 +203,7 @@ jobs:
           printf 'name=native-debug-build-%s-%s\nattempt=%s\n' \
             "$GITHUB_RUN_ID" "$GITHUB_RUN_ATTEMPT" "$GITHUB_RUN_ATTEMPT" >> "$GITHUB_OUTPUT"
       - name: Restore native Cargo dependencies from trusted main
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: |
@@ -269,6 +270,7 @@ jobs:
         id: adapter_key
         run: bash scripts/ci/sdk-adapter-cache-key.sh
       - name: Restore the adapters' Cargo registry and build tree
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
         id: adapter_cargo
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
@@ -590,6 +592,7 @@ jobs:
       # Exact dependency keys include the actual compiler pin, Cargo configuration
       # and vendored crates. Server outputs are discarded before rebuilding.
       - name: Restore native Cargo dependencies from trusted main
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
         id: native_cargo
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
@@ -1316,6 +1319,7 @@ jobs:
       # Exact dependency keys include the actual compiler pin, Cargo configuration
       # and vendored crates. Server outputs are discarded before rebuilding.
       - name: Restore native Cargo dependencies from trusted main
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
         id: native_cargo
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
@@ -2082,6 +2086,7 @@ jobs:
       # Exact dependency keys include the actual compiler pin, Cargo configuration
       # and vendored crates. Server outputs are discarded before rebuilding.
       - name: Restore native Cargo dependencies from trusted main
+        if: ${{ github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository }}
         id: native_cargo
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with: