diff --git a/.github/workflows/verification.yaml b/.github/workflows/verification.yaml
index 8f44aeb..28d983e 100644
--- a/.github/workflows/verification.yaml
+++ b/.github/workflows/verification.yaml
@@ -14,9 +14,7 @@ on:
 jobs:
   verification:
     env:
-      SKY130_PDK_VERSION: 1341f54f5ce0c4955326297f235e4ace1eb6d419
-      PDK_ROOT: /home/runner/pdk
-      MPW_TAG: mpw-9a
+      PDK_ROOT: ${{ github.workspace }}/IHP-Open-PDK
 
     # ubuntu
     runs-on: ubuntu-24.04
@@ -26,12 +24,6 @@ jobs:
         with:
           submodules: recursive
 
-      - name: Install sky130A PDK
-        uses: TinyTapeOut/volare-action@v2
-        with:
-          pdk_version: ${{ env.SKY130_PDK_VERSION }}
-          pdk_root: ${{ env.PDK_ROOT }}
-
       # Set Python up
       - name: setup python
         uses: actions/setup-python@v5
@@ -47,7 +39,7 @@ jobs:
         run: python ./tt/configure.py --update-shuttle --test
 
       # run first set of tests
-      - name: Mux simulation (without caravel)
+      - name: Mux simulation
         working-directory: verilog/dv/mux
         env:
           EXPECTED_REPO: ${{ github.repository }}
@@ -55,3 +47,13 @@ jobs:
           make clean test_mux
           # make will return success even if the test fails, so check for failure in the results.xml
           ! grep failure results.xml
+
+      - name: upload RTL test results
+        if: success() || failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: rtl_test_vcd
+          path: |
+            verilog/dv/mux/results.xml
+            verilog/dv/mux/test_mux.vcd
+            verilog/dv/mux/test_mux.gtkw
diff --git a/tt-multiplexer b/tt-multiplexer
index ba69b2f..b816dfe 160000
--- a/tt-multiplexer
+++ b/tt-multiplexer
@@ -1 +1 @@
-Subproject commit ba69b2f87ea53c6d89256db11840d41431563931
+Subproject commit b816dfedc65740fd205a0c67738c2103cfb572f8
diff --git a/verilog/dv/mux/requirements.txt b/verilog/dv/mux/requirements.txt
index d6f2248..032e564 100644
--- a/verilog/dv/mux/requirements.txt
+++ b/verilog/dv/mux/requirements.txt
@@ -4,7 +4,7 @@
 #
 #    pip-compile
 #
-cocotb==1.8.1
+cocotb==1.9.1
     # via tt-mux (pyproject.toml)
 find-libpython==0.4.0
     # via cocotb