diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index 271d466..614fe8e 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -29,18 +29,18 @@ jobs:
       R_KEEP_PKG_SOURCE: yes
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@ee0669bd1cc54295c223e0bb666b733df41de1c5 # v2
 
-      - uses: r-lib/actions/setup-pandoc@v1
+      - uses: r-lib/actions/setup-pandoc@f5b3dfbf1942ce68283de21bf65cce051e3a2c4d # v1
 
-      - uses: r-lib/actions/setup-r@v1
+      - uses: r-lib/actions/setup-r@f5b3dfbf1942ce68283de21bf65cce051e3a2c4d # v1
         with:
           r-version: ${{ matrix.config.r }}
           http-user-agent: ${{ matrix.config.http-user-agent }}
           use-public-rspm: true
 
-      - uses: r-lib/actions/setup-r-dependencies@v1
+      - uses: r-lib/actions/setup-r-dependencies@f5b3dfbf1942ce68283de21bf65cce051e3a2c4d # v1
         with:
           extra-packages: rcmdcheck
 
-      - uses: r-lib/actions/check-r-package@v1
+      - uses: r-lib/actions/check-r-package@f5b3dfbf1942ce68283de21bf65cce051e3a2c4d # v1