diff --git a/.github/workflows/pr.yaml b/.github/workflows/pr.yaml
index eb904104ad..9fd61e2f4b 100644
--- a/.github/workflows/pr.yaml
+++ b/.github/workflows/pr.yaml
@@ -123,6 +123,12 @@ jobs:
         with:
           cache-prefix: ${{ runner.os }}-${{ hashFiles('.nvmrc') }}
 
+      - name: Setup Python
+        if: ${{ steps.check-image.outputs.is_skipped != 'true' }}
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6.3.0
+        with:
+          python-version: '3.12'
+
       - name: Install Python dependencies
         if: ${{ steps.check-image.outputs.is_skipped != 'true' }}
         run: | 
@@ -185,7 +191,7 @@ jobs:
 
       - name: Run Python tests
         if: ${{ steps.check-image.outputs.is_skipped != 'true' }}
-        run: pytest scripts/install-dynamic-plugins/test_install-dynamic-plugins.py -v --cov=scripts/install-dynamic-plugins --cov-report=lcov:coverage-install-dynamic-plugins.lcov
+        run: python -m pytest scripts/install-dynamic-plugins/test_install-dynamic-plugins.py -v --cov=scripts/install-dynamic-plugins --cov-report=lcov:coverage-install-dynamic-plugins.lcov
 
       - name: Upload install-dynamic-plugins coverage to Codecov
         if: ${{ steps.check-image.outputs.is_skipped != 'true' && !cancelled() }}
diff --git a/scripts/install-dynamic-plugins/install-dynamic-plugins.py b/scripts/install-dynamic-plugins/install-dynamic-plugins.py
index cba2a29aa4..fc176819f5 100755
--- a/scripts/install-dynamic-plugins/install-dynamic-plugins.py
+++ b/scripts/install-dynamic-plugins/install-dynamic-plugins.py
@@ -842,6 +842,10 @@ def install(self, plugin: dict, plugin_path_by_hash: dict) -> str:
         # Extract package
         plugin_path = self._extract_npm_package(archive)
 
+        # Clean up duplicate hashes (same directory, prior config hash on disk)
+        for key in [k for k, v in plugin_path_by_hash.items() if v == plugin_path]:
+            plugin_path_by_hash.pop(key)
+
         return plugin_path
 
     def _extract_npm_package(self, archive: str) -> str:
diff --git a/scripts/install-dynamic-plugins/test_install-dynamic-plugins.py b/scripts/install-dynamic-plugins/test_install-dynamic-plugins.py
index 1056fc99f6..26cfab58da 100644
--- a/scripts/install-dynamic-plugins/test_install-dynamic-plugins.py
+++ b/scripts/install-dynamic-plugins/test_install-dynamic-plugins.py
@@ -1315,6 +1315,36 @@ def test_skip_integrity_check_flag_works(self, tmp_path, mocker):
 
         assert plugin_path == 'test-package-1.0.0'
 
+    def test_install_cleans_up_duplicate_hashes(self, tmp_path, mocker):
+        """Test that npm/local install removes stale hash entries for the same directory."""
+        plugin_path = 'test-plugin-1.0.0'
+        plugin = {
+            'package': '@example/test-plugin',
+            'plugin_hash': 'newhash',
+        }
+        plugin_path_by_hash = {
+            'oldhash': plugin_path,
+            'anotherhash': plugin_path,
+        }
+
+        installer = install_dynamic_plugins.NpmPluginInstaller(
+            str(tmp_path), skip_integrity_check=True,
+        )
+        mocker.patch.object(
+            install_dynamic_plugins,
+            'run_command',
+            return_value=mocker.Mock(stdout='test-plugin-1.0.0.tgz\n'),
+        )
+        mocker.patch.object(
+            installer, '_extract_npm_package', return_value=plugin_path,
+        )
+
+        result = installer.install(plugin, plugin_path_by_hash)
+
+        assert result == plugin_path
+        assert 'oldhash' not in plugin_path_by_hash
+        assert 'anotherhash' not in plugin_path_by_hash
+
 @pytest.mark.integration
 class TestNpmPluginInstallerIntegration:
     """Integration tests with real file operations."""