diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ef91b3852..cea8df2b2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -68,16 +68,12 @@ jobs:
       matrix:
         include:
           ### PyQt 5.7.1 (Python 3.5)
-          # FIXME: Flaky tests / segfault on exit?
           - testenv: py35-pyqt57
             os: ubuntu-16.04
             python: 3.5
-          - testenv: py35-pyqt57
-            os: ubuntu-18.04
-            python: 3.5
           ### PyQt 5.9 (Python 3.6)
           - testenv: py36-pyqt59
-            os: ubuntu-20.04
+            os: ubuntu-18.04
             python: 3.6
           ### PyQt 5.10 (Python 3.6)
           - testenv: py36-pyqt510