diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e7da55a..cd3c21d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -61,6 +61,10 @@ jobs:
             py: "3.14"
           - toxenv: "python3.14t"
             py: "3.14t"
+          - toxenv: "python3.15"
+            py: "3.15"
+          - toxenv: "python3.15t"
+            py: "3.15t"
           - toxenv: "pypy3.8"
             py: "pypy-3.8"
           - toxenv: "pypy3.9"
diff --git a/README.rst b/README.rst
index abf967f..a91fde4 100644
--- a/README.rst
+++ b/README.rst
@@ -31,7 +31,7 @@ Highlights
 Compatibility
 -------------
 
-- CPython 3.8–3.14 (default tox envs).
+- CPython 3.8–3.15 (default tox envs).
 - PyPy 3.8–3.11 (run ``tox -e pypy3.8`` through ``tox -e pypy3.11`` locally; CI mirrors this matrix).
 
 Usage
diff --git a/docs/index.rst b/docs/index.rst
index c5c85ae..ab92c46 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -35,7 +35,7 @@ Highlights
 Compatibility
 -------------
 
-- CPython 3.8–3.14 (default tox envs).
+- CPython 3.8–3.15 (default tox envs).
 - PyPy 3.8–3.11 (run ``tox -e pypy3.8`` through ``tox -e pypy3.11`` locally; CI mirrors this matrix).
 
 Usage
diff --git a/pyproject.toml b/pyproject.toml
index 729488d..eef34f0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,6 +32,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: 3.15",
     "Programming Language :: Python :: 3 :: Only",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
@@ -98,7 +99,7 @@ include = ["src/qs_codec/py.typed"]
 
 [tool.black]
 line-length = 120
-target-version = ["py38", "py39", "py310", "py311", "py312", "py313", "py314"]
+target-version = ["py38", "py39", "py310", "py311", "py312", "py313", "py314", "py315"]
 include = '\.pyi?$'
 exclude = '''
 (
diff --git a/tox.ini b/tox.ini
index 7434d67..2bd3657 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,6 +10,8 @@ envlist =
     python3.13t,
     python3.14,
     python3.14t,
+    python3.15,
+    python3.15t,
     pypy3.8,
     pypy3.9,
     pypy3.10,
@@ -31,6 +33,8 @@ python =
     3.13t: python3.13t
     3.14: python3.14
     3.14t: python3.14t
+    3.15: python3.15
+    3.15t: python3.15t
     pypy-3.8: pypy3.8
     pypy-3.9: pypy3.9
     pypy-3.10: pypy3.10