diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 956545d..c13c5b9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -26,7 +26,7 @@ jobs:
     runs-on: ${{ matrix.runner }}
     steps:
       - name: Checkout zvec-java
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
 
       - name: Setup CMake 3.31
         uses: lukka/get-cmake@latest
@@ -91,7 +91,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout zvec-java
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
 
       - name: Setup Java 25
         uses: actions/setup-java@v4