diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index a717413..1ebeb10 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-latest, macos-latest, windows-latest ]
-        python-version: ['3.12', '3.11']
+        python-version: ['3.12', '3.11', '3.10']
         exclude:
           # tests with ubuntu-latest, python latest
           # are executed by build_docs.yaml
diff --git a/pyproject.toml b/pyproject.toml
index cf71a91..a70b0b3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools >= 61",
-    #'tomli; python_version < "3.11"',
+    'tomli; python_version < "3.11"'
 ]
 build-backend = "setuptools.build_meta"
 
@@ -22,7 +22,7 @@ classifiers = [
     "Programming Language :: Python :: 3 :: Only",
     "Topic :: Scientific/Engineering :: Hydrology",
 ]
-requires-python = ">=3.11"
+requires-python = ">=3.10"
 dependencies = [
     "gis-utils",
     "fiona",