diff --git a/.github/workflows/CI-unixish-docker.yml b/.github/workflows/CI-unixish-docker.yml
index fae61445b286..43494965b3b0 100644
--- a/.github/workflows/CI-unixish-docker.yml
+++ b/.github/workflows/CI-unixish-docker.yml
@@ -43,6 +43,10 @@ jobs:
       # we need to stay at v3 for now because Node 20 does not support the older distros
       # /__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by /__e/node20/bin/node)
       - uses: actions/checkout@v3
+        if: matrix.image == 'ubuntu:16.04' || matrix.image == 'ubuntu:18.04'
+
+      - uses: actions/checkout@v4
+        if: matrix.image != 'ubuntu:16.04' && matrix.image != 'ubuntu:18.04'
 
       - name: Install missing software on ubuntu
         if: contains(matrix.image, 'ubuntu')
@@ -58,9 +62,19 @@ jobs:
       # needs to be called after the package installation since
       # - it doesn't call "apt-get update"
       #
-      # needs to be to fixated on 1.2.11 so it works with older images - see https://github.com/hendrikmuhs/ccache-action/issues/178
+      # needs to be to fixated on 1.2.11 so it works with older images - see https://github.com/hendrikmuhs/ccache-action/issues/178.
+      # using the older version will cause a two minute hang in its post-run step.
       - name: ccache
         uses: hendrikmuhs/ccache-action@v1.2.11
+        if: matrix.image == 'ubuntu:16.04' || matrix.image == 'ubuntu:18.04'
+        with:
+          key: ${{ github.workflow }}-${{ matrix.image }}
+
+      # needs to be called after the package installation since
+      # - it doesn't call "apt-get update"
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2
+        if: matrix.image != 'ubuntu:16.04' && matrix.image != 'ubuntu:18.04'
         with:
           key: ${{ github.workflow }}-${{ matrix.image }}
 
@@ -108,6 +122,10 @@ jobs:
       # we need to stay at v3 for now because Node 20 does not support the older distros
       # /__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by /__e/node20/bin/node)
       - uses: actions/checkout@v3
+        if: matrix.image == 'ubuntu:16.04' || matrix.image == 'ubuntu:18.04'
+
+      - uses: actions/checkout@v4
+        if: matrix.image != 'ubuntu:16.04' && matrix.image != 'ubuntu:18.04'
 
       - name: Install missing software on ubuntu
         if: contains(matrix.image, 'ubuntu')
@@ -118,9 +136,19 @@ jobs:
       # needs to be called after the package installation since
       # - it doesn't call "apt-get update"
       #
-      # needs to be to fixated on 1.2.11 so it works with older images - see https://github.com/hendrikmuhs/ccache-action/issues/178
+      # needs to be to fixated on 1.2.11 so it works with older images - see https://github.com/hendrikmuhs/ccache-action/issues/178.
+      # using the older version will cause a two minute hang in its post-run step.
       - name: ccache
         uses: hendrikmuhs/ccache-action@v1.2.11
+        if: matrix.image == 'ubuntu:16.04' || matrix.image == 'ubuntu:18.04'
+        with:
+          key: ${{ github.workflow }}-${{ matrix.image }}
+
+      # needs to be called after the package installation since
+      # - it doesn't call "apt-get update"
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2
+        if: matrix.image != 'ubuntu:16.04' && matrix.image != 'ubuntu:18.04'
         with:
           key: ${{ github.workflow }}-${{ matrix.image }}