diff --git a/.github/workflows/devdax.yml b/.github/workflows/devdax.yml
index 3f2b3afc9..e8a4dc3bd 100644
--- a/.github/workflows/devdax.yml
+++ b/.github/workflows/devdax.yml
@@ -1,7 +1,7 @@
 # This workflow builds and tests the devdax memory provider.
 # It requires a DAX device (e.g. /dev/dax0.0) configured in the OS.
-# This DAX device should be specified using UMF_TESTS_DEVDAX_PATH and UMF_TESTS_DEVDAX_SIZE
-# CI environment variables.
+# This DAX device should be specified using the
+# UMF_TESTS_DEVDAX_PATH and UMF_TESTS_DEVDAX_SIZE environment variables.
 
 name: DevDax
 
@@ -11,8 +11,7 @@ permissions:
   contents: read
 
 env:
-  UMF_TESTS_DEVDAX_PATH : "/dev/dax0.0"
-  UMF_TESTS_DEVDAX_SIZE : 1054867456
+  UMF_TESTS_DEVDAX_NAMESPACE : "0.0"
   BUILD_DIR : "${{github.workspace}}/build"
   INSTL_DIR : "${{github.workspace}}/../install-dir"
 
@@ -28,10 +27,12 @@ jobs:
 
     runs-on: ["DSS-DEVDAX", "DSS-Ubuntu"]
     steps:
-      - name: Check if the devdax exists
+      - name: Check if the devdax exists, print out UMF_TESTS_DEVDAX_PATH and UMF_TESTS_DEVDAX_SIZE
         run: |
           ndctl list -N --device-dax
-          ls -al ${{env.UMF_TESTS_DEVDAX_PATH}}
+          ls -al /dev/dax${UMF_TESTS_DEVDAX_NAMESPACE}
+          echo UMF_TESTS_DEVDAX_PATH="/dev/dax${UMF_TESTS_DEVDAX_NAMESPACE}"
+          echo UMF_TESTS_DEVDAX_SIZE="$(ndctl list --namespace=namespace${UMF_TESTS_DEVDAX_NAMESPACE} | grep size | cut -d':' -f2 | cut -d',' -f1)"
 
       - name: Checkout
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -63,4 +64,7 @@ jobs:
 
       - name: Run only devdax tests
         working-directory: ${{env.BUILD_DIR}}
-        run: ctest -C ${{matrix.build_type}} -R devdax -V
+        run: >
+          UMF_TESTS_DEVDAX_PATH="/dev/dax${UMF_TESTS_DEVDAX_NAMESPACE}"
+          UMF_TESTS_DEVDAX_SIZE="$(ndctl list --namespace=namespace${UMF_TESTS_DEVDAX_NAMESPACE} | grep size | cut -d':' -f2 | cut -d',' -f1)"
+          ctest -C ${{matrix.build_type}} -R devdax -V