diff --git a/.github/workflows/doxygen-github-pages.yml b/.github/workflows/doxygen-github-pages.yml
index 6ed20e6f..d65de92b 100644
--- a/.github/workflows/doxygen-github-pages.yml
+++ b/.github/workflows/doxygen-github-pages.yml
@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Set Actions Allow Unsecure Commands (temporary)
         run: |
diff --git a/.github/workflows/spelling.yml b/.github/workflows/spelling.yml
index db74f454..43219140 100644
--- a/.github/workflows/spelling.yml
+++ b/.github/workflows/spelling.yml
@@ -5,7 +5,7 @@ on:
 jobs:
   build:
     name: Spell checking
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - uses: actions/checkout@v2.0.0
       with: