diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 12fad62b..79a5af3b 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -16,7 +16,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macos-10.15,macos-11.0]
+        os: [macos-11.0]
         qt_ver: [5.15.2]
         qt_arch: [clang_64]
     env:
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 8ce06b28..362c5e45 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -18,7 +18,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-18.04,ubuntu-20.04]
+        os: [ubuntu-20.04]
         qt_ver: [5.15.2]
         qt_arch: [gcc_64]
     env: