diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 328ea7a..d3aa60e 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -53,3 +53,33 @@ jobs:
 
       - name: Run tests
         run: uvx --with tox-uv tox -e ${{ matrix.python-version }}
+
+      - name: Upload coverage data
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          include-hidden-files: true
+          name: coverage-data-${{ matrix.os }}-py${{ matrix.python-version }}
+          path: ".coverage.*"
+
+  coverage:
+    name: Coverage
+    runs-on: ubuntu-latest
+    needs: test
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+
+      - name: Download coverage data
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
+        with:
+          pattern: coverage-data-*
+          merge-multiple: true
+
+      - name: Set up Python
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@d9e0f98d3fc6adb07d1e3d37f3043649ddad06a1 # v6.5.0
+
+      - name: Combine coverage data and generate report
+        run: uvx --with tox-uv tox -e coverage
diff --git a/.gitignore b/.gitignore
index e34e050..ce7b10e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,4 @@ dist/
 .vscode
 .python-version
 .tox/
+coverage.xml
diff --git a/pyproject.toml b/pyproject.toml
index 7ff220a..5453ac1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -45,9 +45,9 @@ dev = [
     "types-requests>=2.27.20",
 ]
 tests = [
+    "coverage>=7.2.7",
     "pytest>=7.1.2",
     "pytest-asyncio>=0.18.3",
-    "pytest-cov>=3.0.0",
     "requests>=2.26.0",
     "responses>=0.20.0",
 ]
@@ -75,13 +75,50 @@ env_list = [
 [tool.tox.env_run_base]
 description = "run unit tests"
 dependency_groups = [ "tests" ]
-commands = [ [ "pytest", { replace = "posargs", default = [ "tests" ], extend = true } ] ]
+commands = [ [ "coverage", "run", "-m", "pytest", { replace = "posargs", default = [ "tests" ], extend = true } ] ]
+
+[tool.tox.env.coverage]
+description = "generate coverage report"
+depends = [
+  "3.7",
+  "3.8",
+  "3.9",
+  "3.10",
+  "3.11",
+  "3.12",
+  "3.13",
+  "3.14",
+]
+dependency_groups = [ "tests" ]
+commands = [
+  [ "coverage", "combine" ],
+  [ "coverage", "report" ],
+  [ "coverage", "xml" ],
+]
 
 [tool.pytest.ini_options]
 filterwarnings = [
     "error",
 ]
 
+[tool.coverage.paths]
+package = [
+  "backoff/",
+  "*/site-packages/backoff/",
+]
+
+[tool.coverage.report]
+fail_under = 100
+show_missing = true
+
+[tool.coverage.run]
+branch = true
+parallel = true
+relative_files = true
+source = [
+  "backoff",
+]
+
 [build-system]
 requires = ["hatchling"]
 build-backend = "hatchling.build"
diff --git a/uv.lock b/uv.lock
index cf5e4ea..9ba4459 100644
--- a/uv.lock
+++ b/uv.lock
@@ -15,6 +15,9 @@ source = { editable = "." }
 
 [package.dev-dependencies]
 dev = [
+    { name = "coverage", version = "7.2.7", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
+    { name = "coverage", version = "7.6.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
+    { name = "coverage", version = "7.10.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
     { name = "flake8", version = "5.0.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8.1'" },
     { name = "flake8", version = "7.1.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.8.1' and python_full_version < '3.9'" },
     { name = "flake8", version = "7.3.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
@@ -27,9 +30,6 @@ dev = [
     { name = "pytest-asyncio", version = "0.21.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
     { name = "pytest-asyncio", version = "0.24.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
     { name = "pytest-asyncio", version = "1.1.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
-    { name = "pytest-cov", version = "4.1.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
-    { name = "pytest-cov", version = "5.0.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
-    { name = "pytest-cov", version = "6.2.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
     { name = "requests", version = "2.31.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
     { name = "requests", version = "2.32.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
     { name = "requests", version = "2.32.5", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
@@ -40,15 +40,15 @@ dev = [
     { name = "types-requests", version = "2.32.4.20250809", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
 ]
 tests = [
+    { name = "coverage", version = "7.2.7", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
+    { name = "coverage", version = "7.6.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
+    { name = "coverage", version = "7.10.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
     { name = "pytest", version = "7.4.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
     { name = "pytest", version = "8.3.5", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
     { name = "pytest", version = "8.4.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
     { name = "pytest-asyncio", version = "0.21.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
     { name = "pytest-asyncio", version = "0.24.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
     { name = "pytest-asyncio", version = "1.1.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
-    { name = "pytest-cov", version = "4.1.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
-    { name = "pytest-cov", version = "5.0.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
-    { name = "pytest-cov", version = "6.2.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
     { name = "requests", version = "2.31.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
     { name = "requests", version = "2.32.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
     { name = "requests", version = "2.32.5", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
@@ -60,19 +60,19 @@ tests = [
 
 [package.metadata.requires-dev]
 dev = [
+    { name = "coverage", specifier = ">=7.2.7" },
     { name = "flake8", specifier = ">=4.0.1" },
     { name = "mypy", specifier = ">=0.942" },
     { name = "pytest", specifier = ">=7.1.2" },
     { name = "pytest-asyncio", specifier = ">=0.18.3" },
-    { name = "pytest-cov", specifier = ">=3.0.0" },
     { name = "requests", specifier = ">=2.26.0" },
     { name = "responses", specifier = ">=0.20.0" },
     { name = "types-requests", specifier = ">=2.27.20" },
 ]
 tests = [
+    { name = "coverage", specifier = ">=7.2.7" },
     { name = "pytest", specifier = ">=7.1.2" },
     { name = "pytest-asyncio", specifier = ">=0.18.3" },
-    { name = "pytest-cov", specifier = ">=3.0.0" },
     { name = "requests", specifier = ">=2.26.0" },
     { name = "responses", specifier = ">=0.20.0" },
 ]
@@ -260,11 +260,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/67/fb/b3b1d7887e1ea25a9608b0776e480e4bbc303ca95a31fd585555ec4fff5a/coverage-7.2.7-pp37.pp38.pp39-none-any.whl", hash = "sha256:b7b4c971f05e6ae490fef852c218b0e79d4e52f79ef0c8475566584a8fb3e01d", size = 193207, upload-time = "2023-05-29T20:08:48.153Z" },
 ]
 
-[package.optional-dependencies]
-toml = [
-    { name = "tomli", version = "2.0.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
-]
-
 [[package]]
 name = "coverage"
 version = "7.6.1"
@@ -348,11 +343,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/a5/2b/0354ed096bca64dc8e32a7cbcae28b34cb5ad0b1fe2125d6d99583313ac0/coverage-7.6.1-pp38.pp39.pp310-none-any.whl", hash = "sha256:e9a6e0eb86070e8ccaedfbd9d38fec54864f3125ab95419970575b42af7541df", size = 198926, upload-time = "2024-08-04T19:45:28.875Z" },
 ]
 
-[package.optional-dependencies]
-toml = [
-    { name = "tomli", version = "2.2.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
-]
-
 [[package]]
 name = "coverage"
 version = "7.10.4"
@@ -451,11 +441,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/bb/78/983efd23200921d9edb6bd40512e1aa04af553d7d5a171e50f9b2b45d109/coverage-7.10.4-py3-none-any.whl", hash = "sha256:065d75447228d05121e5c938ca8f0e91eed60a1eb2d1258d42d5084fecfc3302", size = 208365, upload-time = "2025-08-17T00:26:41.479Z" },
 ]
 
-[package.optional-dependencies]
-toml = [
-    { name = "tomli", version = "2.2.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9' and python_full_version <= '3.11'" },
-]
-
 [[package]]
 name = "exceptiongroup"
 version = "1.3.0"
@@ -1026,56 +1011,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/c7/9d/bf86eddabf8c6c9cb1ea9a869d6873b46f105a5d292d3a6f7071f5b07935/pytest_asyncio-1.1.0-py3-none-any.whl", hash = "sha256:5fe2d69607b0bd75c656d1211f969cadba035030156745ee09e7d71740e58ecf", size = 15157, upload-time = "2025-07-16T04:29:24.929Z" },
 ]
 
-[[package]]
-name = "pytest-cov"
-version = "4.1.0"
-source = { registry = "https://pypi.org/simple" }
-resolution-markers = [
-    "python_full_version < '3.8'",
-]
-dependencies = [
-    { name = "coverage", version = "7.2.7", source = { registry = "https://pypi.org/simple" }, extra = ["toml"], marker = "python_full_version < '3.8'" },
-    { name = "pytest", version = "7.4.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.8'" },
-]
-sdist = { url = "https://files.pythonhosted.org/packages/7a/15/da3df99fd551507694a9b01f512a2f6cf1254f33601605843c3775f39460/pytest-cov-4.1.0.tar.gz", hash = "sha256:3904b13dfbfec47f003b8e77fd5b589cd11904a21ddf1ab38a64f204d6a10ef6", size = 63245, upload-time = "2023-05-24T18:44:56.845Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/a7/4b/8b78d126e275efa2379b1c2e09dc52cf70df16fc3b90613ef82531499d73/pytest_cov-4.1.0-py3-none-any.whl", hash = "sha256:6ba70b9e97e69fcc3fb45bfeab2d0a138fb65c4d0d6a41ef33983ad114be8c3a", size = 21949, upload-time = "2023-05-24T18:44:54.079Z" },
-]
-
-[[package]]
-name = "pytest-cov"
-version = "5.0.0"
-source = { registry = "https://pypi.org/simple" }
-resolution-markers = [
-    "python_full_version >= '3.8.1' and python_full_version < '3.9'",
-    "python_full_version >= '3.8' and python_full_version < '3.8.1'",
-]
-dependencies = [
-    { name = "coverage", version = "7.6.1", source = { registry = "https://pypi.org/simple" }, extra = ["toml"], marker = "python_full_version == '3.8.*'" },
-    { name = "pytest", version = "8.3.5", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.8.*'" },
-]
-sdist = { url = "https://files.pythonhosted.org/packages/74/67/00efc8d11b630c56f15f4ad9c7f9223f1e5ec275aaae3fa9118c6a223ad2/pytest-cov-5.0.0.tar.gz", hash = "sha256:5837b58e9f6ebd335b0f8060eecce69b662415b16dc503883a02f45dfeb14857", size = 63042, upload-time = "2024-03-24T20:16:34.856Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/78/3a/af5b4fa5961d9a1e6237b530eb87dd04aea6eb83da09d2a4073d81b54ccf/pytest_cov-5.0.0-py3-none-any.whl", hash = "sha256:4f0764a1219df53214206bf1feea4633c3b558a2925c8b59f144f682861ce652", size = 21990, upload-time = "2024-03-24T20:16:32.444Z" },
-]
-
-[[package]]
-name = "pytest-cov"
-version = "6.2.1"
-source = { registry = "https://pypi.org/simple" }
-resolution-markers = [
-    "python_full_version >= '3.9'",
-]
-dependencies = [
-    { name = "coverage", version = "7.10.4", source = { registry = "https://pypi.org/simple" }, extra = ["toml"], marker = "python_full_version >= '3.9'" },
-    { name = "pluggy", version = "1.6.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
-    { name = "pytest", version = "8.4.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.9'" },
-]
-sdist = { url = "https://files.pythonhosted.org/packages/18/99/668cade231f434aaa59bbfbf49469068d2ddd945000621d3d165d2e7dd7b/pytest_cov-6.2.1.tar.gz", hash = "sha256:25cc6cc0a5358204b8108ecedc51a9b57b34cc6b8c967cc2c01a4e00d8a67da2", size = 69432, upload-time = "2025-06-12T10:47:47.684Z" }
-wheels = [
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-
 [[package]]
 name = "pyyaml"
 version = "6.0.1"