diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 35a7d06..b7187a0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,10 +39,10 @@ jobs:
     timeout-minutes: 10
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
 
       - name: Cache Swift Package Manager dependencies
-        uses: actions/cache@v5
+        uses: actions/cache@caa296126883cff596d87d8935842f9db880ef25 # v5.1.0
         with:
           path: |
             ~/.cache/org.swift.swiftpm
@@ -82,10 +82,10 @@ jobs:
     timeout-minutes: 10
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
 
       - name: Cache Swift Package Manager dependencies
-        uses: actions/cache@v5
+        uses: actions/cache@caa296126883cff596d87d8935842f9db880ef25 # v5.1.0
         with:
           path: |
             ~/.cache/org.swift.swiftpm