diff --git a/.github/workflows/comprehensive-tests.yml b/.github/workflows/comprehensive-tests.yml
index 15fb575..e20729e 100644
--- a/.github/workflows/comprehensive-tests.yml
+++ b/.github/workflows/comprehensive-tests.yml
@@ -95,14 +95,14 @@ jobs:
           fail_ci_if_error: false
 
       - name: Upload test results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: test-results-unit-${{ matrix.python-version }}
           path: junit/test-results-*.xml
 
       - name: Upload coverage HTML
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: coverage-html-unit-${{ matrix.python-version }}
@@ -162,7 +162,7 @@ jobs:
           fail_ci_if_error: false
 
       - name: Upload test results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: test-results-api
@@ -236,7 +236,7 @@ jobs:
           fi
 
       - name: Upload test results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: test-results-integration
@@ -349,7 +349,7 @@ jobs:
           bandit -r server/ client/ -f json -o bandit-report.json || echo "⚠️ Bandit found security issues (advisory only)"
 
       - name: Upload security scan results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: security-scan-results
@@ -402,7 +402,7 @@ jobs:
           fi
 
       - name: Upload benchmark results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: benchmark-results