diff --git a/.circleci/config.yml b/.circleci/config.yml
index 47b0e00e..f1bab746 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -165,7 +165,7 @@ jobs:
 
   test_package:
     docker:
-      - image: cimg/python:3.9
+      - image: cimg/python:3.10
         auth:
           username: $DOCKER_USER
           password: $DOCKER_PAT
@@ -217,7 +217,7 @@ jobs:
 
   deploy_pypi:
     docker:
-      - image: cimg/python:3.9
+      - image: cimg/python:3.10
         auth:
           username: $DOCKER_USER
           password: $DOCKER_PAT
diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index 0e9dcb48..25bca100 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -66,17 +66,17 @@ jobs:
     needs: [cache-test-data]
     strategy:
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
         dependencies: [latest, pre]
         include:
-          - python-version: "3.9"
+          - python-version: "3.10"
             dependencies: min
         exclude:
           # Do not test pre-releases for versions out of SPEC0
-          - python-version: "3.9"
-            dependencies: pre
           - python-version: "3.10"
             dependencies: pre
+          - python-version: "3.11"
+            dependencies: pre
 
     env:
       DEPENDS: ${{ matrix.dependencies }}
diff --git a/pyproject.toml b/pyproject.toml
index a6ac0859..c4a1b8e4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,7 +11,6 @@ classifiers = [
     "Intended Audience :: Science/Research",
     "Topic :: Scientific/Engineering :: Image Recognition",
     "License :: OSI Approved :: BSD License",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
@@ -19,12 +18,12 @@ classifiers = [
 ]
 description = "NiTransforms -- Neuroimaging spatial transforms in Python."
 license = {text = "MIT License"}
-requires-python = ">= 3.9"
+requires-python = ">= 3.10"
 dependencies = [
-    "numpy >= 1.21",
+    "numpy >= 2.1",
     "scipy >= 1.8",
-    "nibabel >= 4.0",
-    "h5py >= 3.9",
+    "nibabel >= 5.2",
+    "h5py >= 3.11",
 ]
 dynamic = ["version"]
 
@@ -34,9 +33,9 @@ Manuscript = "https://doi.org/10.31219/osf.io/8aq7b"
 NiBabel = "https://github.com/nipy/nibabel/pull/656"
 
 [project.optional-dependencies]
-niftiext = ["lxml >= 4.6"]
+niftiext = ["lxml >= 4.6.4"]
 test = [
-    "pytest >= 6",
+    "pytest >= 6.2.5",
     "pytest-cov >= 2.11",
     "pytest-env",
     "pytest-xdist >= 2.5",
diff --git a/tox.ini b/tox.ini
index 50d167bc..013ec4dd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,15 +2,14 @@
 requires =
   tox>=4
 envlist =
-  py3{9,10,11,12,13}-latest
-  py39-min
+  py3{10,11,12,13}-latest
+  py310-min
   py3{11,12,13}-pre
 skip_missing_interpreters = true
 
 # Configuration that allows us to split tests across GitHub runners effectively
 [gh-actions]
 python =
-  3.9: py39
   3.10: py310
   3.11: py311
   3.12: py312