diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b9270141f..9f21f83c4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,6 +19,21 @@ jobs:
         uses: actions/checkout@v2
         with:
             path: ./kernel
+      - name: Install spell
+        run: |
+          sudo apt-get install spell
+          sudo apt-get install util-linux
+      - name: Check spelling
+        run: |
+          PATH=$PATH:main/tools/spell
+          # Make sure that the portable directory is not included in the spellcheck.
+          sed -i 's/find $DIRNAME/find $DIRNAME -not -path '*portable*'/g' main/tools/spell/find-unknown-comment-words
+          find-unknown-comment-words --directory kernel/
+          if [ "$?" = "0" ]; then
+            exit 0
+          else
+            exit 1
+          fi
   url-check:
     runs-on: ubuntu-latest
       - name: URL Checker