diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index fc496a5..aba758e 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -23,7 +23,7 @@ jobs:
       run:
         shell: bash -el {0}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3
 
       - uses: conda-incubator/setup-miniconda@d2e6a045a86077fb6cad6f5adf368e9076ddaa8d # v3.1.0
         with: