diff --git a/.github/workflows/PR_build.yml b/.github/workflows/PR_build.yml
index 1f8a3ea9..73bb862f 100644
--- a/.github/workflows/PR_build.yml
+++ b/.github/workflows/PR_build.yml
@@ -20,7 +20,6 @@ jobs:
           sudo add-apt-repository -yn 'deb http://archive.ubuntu.com/ubuntu/ xenial universe' 
           sudo add-apt-repository -yn 'deb http://archive.ubuntu.com/ubuntu/ bionic main'
           sudo add-apt-repository -yn 'deb http://archive.ubuntu.com/ubuntu/ bionic universe' 
-          sudo add-apt-repository -yn 'deb http://mirrors.kernel.org/ubuntu hirsute main universe' 
           sudo apt-get update
           sudo apt-get install -y gcc-${{ matrix.gcc }} g++-${{ matrix.gcc }}
       - name: Checkout
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 90953049..a9a47a06 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -34,7 +34,6 @@ jobs:
           sudo add-apt-repository -yn 'deb http://archive.ubuntu.com/ubuntu/ xenial universe' 
           sudo add-apt-repository -yn 'deb http://archive.ubuntu.com/ubuntu/ bionic main'
           sudo add-apt-repository -yn 'deb http://archive.ubuntu.com/ubuntu/ bionic universe' 
-          sudo add-apt-repository -yn 'deb http://mirrors.kernel.org/ubuntu hirsute main universe' 
           sudo apt-get update
           sudo apt-get install -y gcc-${{ matrix.gcc }} g++-${{ matrix.gcc }}
       - name: Checkout