diff --git a/.github/workflows/dl_cpu.yml b/.github/workflows/dl_cpu.yml
index 2a7d9eea41..1abe7e1f12 100644
--- a/.github/workflows/dl_cpu.yml
+++ b/.github/workflows/dl_cpu.yml
@@ -17,24 +17,38 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
-      # max-parallel: 6
+      max-parallel: 6
       matrix:
-        os: [ubuntu-18.04, macOS-10.15]  # windows-2019,
+        os: [ubuntu-18.04, ubuntu-20.04, macOS-10.15]  # windows-2019,
         python-version: [3.6, 3.7, 3.8]
         requirements: ['minimal', 'latest']
         exclude:
-          # pypi problems
-          - python-version: 3.8
-            requirements: 'minimal'
-          - python-version: 3.7
-            requirements: 'minimal'
           # pickle problems
           - python-version: 3.8
             os: macOS-10.15
           - python-version: 3.6
             os: macOS-10.15
+          # github CI problems
+          - python-version: 3.8
+            os: ubuntu-18.04
+            requirements: minimal
+          - python-version: 3.8
+            os: ubuntu-20.04
+            requirements: minimal
+#           - python-version: 3.7
+#             os: macOS-10.15
+#             requirements: minimal
+#           - python-version: 3.6
+#             os: ubuntu-18.04
+#             requirements: minimal
+#           - python-version: 3.7
+#             os: ubuntu-18.04
+#             requirements: minimal
+#           - python-version: 3.7
+#             os: ubuntu-20.04
+#             requirements: minimal
 
-    timeout-minutes: 120
+    timeout-minutes: 30
     steps:
       - uses: actions/checkout@v2
 
diff --git a/requirements/requirements-ml.txt b/requirements/requirements-ml.txt
index e480e4d941..e9bff09eeb 100644
--- a/requirements/requirements-ml.txt
+++ b/requirements/requirements-ml.txt
@@ -1,4 +1,4 @@
-scipy
-matplotlib
-pandas>=0.22
-scikit-learn>=0.20
+scipy>=1.3.0
+matplotlib>=3.1.0
+pandas>=0.25.0
+scikit-learn>=0.21.0