diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3988f16..193cf9d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,23 +11,23 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
       - name: Set up Java
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4
         with:
           distribution: temurin
           java-version: 21
 
       - name: Install Clojure tools
-        uses: DeLaGuardo/setup-clojure@13.3
+        uses: DeLaGuardo/setup-clojure@1fb06179c376b10a4da4c778e1c794ef5a0df302 # 13.3
         with:
           cli: latest
           bb: latest
           clj-kondo: latest
 
       - name: Cache Clojure dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
         with:
           path: |
             ~/.m2/repository