diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 3e6bc1b08..8169f21ab 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -5,14 +5,14 @@ on: [push]
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-16.04
     strategy:
       matrix:
         OMR_TARGET: ['x86_64','x86']
 
     steps:
     - name: Prepare
-      run: sudo apt-get install -yq build-essential git unzip ncurses-dev libz-dev libssl-dev python subversion gettext gawk wget curl rsync perl libelf-dev python3 libpython3-stdlib liblzma-dev
+      run: sudo apt-get install -yq build-essential git unzip ncurses-dev libz-dev libssl-dev python subversion gettext gawk wget curl rsync perl libelf-dev python3.5 libpython3.5-stdlib liblzma-dev
     - name: Build toolchain
       env:
         OMR_TARGET: ${{matrix.OMR_TARGET}}
@@ -27,6 +27,7 @@ jobs:
         export OMR_FEED_SRC="${{ github.sha }}"
         pwd
         ls
+        pyenv global 3.5.2
         sh build.sh prepare {tools,toolchain}/install -j6
         #echo -e "$OMR_PRIVKEY" > /home/runner/work/openmptcprouter-feeds/openmptcprouter-feeds/openmptcprouter/${{ env.OMR_TARGET }}/source/key-build
         #echo -e "$OMR_PUBKEY" > /home/runner/work/openmptcprouter-feeds/openmptcprouter-feeds/openmptcprouter/${{ env.OMR_TARGET }}/source/key-build.pub