diff --git a/.github/workflows/performance.yml b/.github/workflows/performance.yml
index 3c2752c1f..a0fbc78cc 100644
--- a/.github/workflows/performance.yml
+++ b/.github/workflows/performance.yml
@@ -20,7 +20,7 @@ on:
   workflow_dispatch:
     inputs:
       testbeds:
-        default: '["basic-01","basic-02"]'
+        default: 'basic-01,basic-02'
         description: 'Testbed(s) to test'
         required: false
 
@@ -117,12 +117,11 @@ jobs:
     - name: generate-matrix
       id: set-matrix
       run: |
-        set -x
-        TESTBEDS="${{ github.event.inputs.testbeds || '[\"basic-01\",\"basic-02\"]' }}"
-        echo "$TESTBEDS"
-        TESTBED_ARRAY=$(echo "$TESTBEDS" | jq -c 'map({"testbed":.})')
-        echo "$TESTBED_ARRAY"
-        echo "::set-output name=matrix::{\"include\":${TESTBED_ARRAY}}"
+        TESTBEDS="${{ github.event.inputs.testbeds || 'basic-01,basic-02' }}"
+        # convert to JSON array
+        TESTBEDS=$(echo $TESTBEDS | sed "s/,/\",\"/g" | sed 's/^/[\"/g' | sed 's/$/\"]/g')
+        TESTBEDS=$(echo "$TESTBEDS" | jq -c 'map({"testbed":.})')
+        echo "::set-output name=matrix::{\"include\":${TESTBEDS}}"
 
   test:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/sanity.yml b/.github/workflows/sanity.yml
index 3a0669e72..e8670d976 100644
--- a/.github/workflows/sanity.yml
+++ b/.github/workflows/sanity.yml
@@ -20,7 +20,7 @@ on:
   workflow_dispatch:
     inputs:
       testbeds:
-        default: '["basic-01","basic-02"]'
+        default: 'basic-01,basic-02'
         description: 'Testbed(s) to test'
         required: false
       marker_expression:
@@ -123,12 +123,10 @@ jobs:
     - name: generate-matrix
       id: set-matrix
       run: |
-        set -x
-        TESTBEDS="${{ github.event.inputs.testbeds || '[\"basic-01\",\"basic-02\"]' }}"
-        echo "$TESTBEDS"
-        TESTBED_ARRAY=$(echo "$TESTBEDS" | jq -c 'map({"testbed":.})')
-        echo "$TESTBED_ARRAY"
-        echo "::set-output name=matrix::{\"include\":${TESTBED_ARRAY}}"
+        TESTBEDS="${{ github.event.inputs.testbeds || 'basic-01,basic-02' }}"
+        TESTBEDS=$(echo $TESTBEDS | sed "s/,/\",\"/g" | sed 's/^/[\"/g' | sed 's/$/\"]/g')
+        TESTBEDS=$(echo "$TESTBEDS" | jq -c 'map({"testbed":.})')
+        echo "::set-output name=matrix::{\"include\":${TESTBEDS}}"
 
   test:
     runs-on: ubuntu-latest