diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 2f72ab54ff..1a82a12739 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -53,7 +53,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ['ubuntu-latest', 'macos-latest']
-        python: ['3.6', '3.7', '3.8']
+        python: ['3.6', '3.7', '3.8', '3.9']
 
     runs-on: ${{ matrix.os }}
 
diff --git a/pyproject.toml b/pyproject.toml
index 8965069423..930320fbc4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,2 +1,2 @@
 [build-system]
-requires = ["setuptools", "setuptools_scm", "wheel", "scikit-build", "cmake", "ninja", "libecl"]
+requires = ["setuptools", "setuptools_scm", "wheel", "scikit-build", "cmake", "ninja", "ecl"]