diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f3e2690..77c03ca 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -12,7 +12,7 @@ jobs:
     strategy:
       matrix:
         os: [windows-latest, ubuntu-latest, macos-latest]
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        python-version: ['3.10', '3.11', '3.12', '3.13']
     defaults:
       run:
         shell: bash
diff --git a/pyproject.toml b/pyproject.toml
index ab1d4d8..4c2a5bd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,13 +8,13 @@ version = "1.3.0"
 description = "IMAP SDC Data Access"
 authors = [{name = "IMAP SDC Developers", email = "imap-sdc@lists.lasp.colorado.edu"}]
 readme = "README.md"
+requires-python = ">=3.10"
 license = "MIT"
 keywords = ["IMAP", "SDC", "SOC", "SDS", "Science Operations"]
 classifiers = [
     "Development Status :: 3 - Alpha",
     "Natural Language :: English",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",