diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 67146401e..1a73b996d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ on:
 jobs:
   # 1. Unit/Integration Test
   unit-integration-test:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-18.04
     env:
       MIX_ENV: test
       POSTGRES_HOST: localhost
@@ -45,7 +45,7 @@ jobs:
   # 2. Build VM image
   build-vm:
     needs: unit-integration-test
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
       - name: Build VM Image
@@ -61,7 +61,7 @@ jobs:
   # 3. Functional Test
   functional-test:
     needs: build-vm
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
       - name: Functional Test