diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 98f8d8a..0307b45 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -131,6 +131,9 @@
       - name: Install gcc-${{ env.GCC_VER }}
         if:  matrix.compiler == 'gcc'
         run: |
+          # ubuntu-toolchain-r/test PPA for gcc-13 compiler
+          sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
+          sudo apt-get update -y
           sudo apt-get install -y gcc-${{ env.GCC_VER }}:${{ matrix.architecture }}
           sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-${{ env.GCC_VER }} 100
           sudo update-alternatives --set gcc /usr/bin/gcc-${{ env.GCC_VER }}