diff --git a/HISTORY.md b/HISTORY.md
index 2a9f7824..213e5efe 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -10,6 +10,7 @@
 - `pathlib.Path` is now supported by default.
   ([#81](https://github.com/python-attrs/cattrs/issues/81))
 - Add `cbor2` serialization library to the `cattr.preconf` package.
+- Add optional dependencies for `cattrs.preconf` third-party libraries. ([#337](https://github.com/python-attrs/cattrs/pull/337))
 
 ## 22.2.0 (2022-10-03)
 
diff --git a/docs/preconf.md b/docs/preconf.md
index d0e7db2f..945e7642 100644
--- a/docs/preconf.md
+++ b/docs/preconf.md
@@ -42,6 +42,17 @@ All preconf converters now have `loads` and `dumps` methods, which combine un/st
 
 Particular libraries may have additional constraints documented below.
 
+Third-party libraries can be specified as optional (extra) dependencies on `cattrs` during installation.
+Optional install targets should match the name of the {mod}`cattrs.preconf` modules.
+
+```console
+# Using pip
+pip install cattrs[ujson]
+
+# Using poetry
+poetry add --extras tomlkit cattrs
+```
+
 ## Standard Library _json_
 
 Found at {mod}`cattrs.preconf.json`.
diff --git a/poetry.lock b/poetry.lock
index 7199c712..71e8b1d7 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.4.0 and should not be changed by hand.
 
 [[package]]
 name = "alabaster"
@@ -106,8 +106,8 @@ uvloop = ["uvloop (>=0.15.2)"]
 name = "cbor2"
 version = "5.4.6"
 description = "CBOR (de)serializer with extensive tag support"
-category = "dev"
-optional = false
+category = "main"
+optional = true
 python-versions = ">=3.7"
 files = [
     {file = "cbor2-5.4.6-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:309fffbb7f561d67f02095d4b9657b73c9220558701c997e9bfcfbca2696e927"},
@@ -286,8 +286,8 @@ files = [
 name = "dnspython"
 version = "2.1.0"
 description = "DNS toolkit"
-category = "dev"
-optional = false
+category = "main"
+optional = true
 python-versions = ">=3.6"
 files = [
     {file = "dnspython-2.1.0-py3-none-any.whl", hash = "sha256:95d12f6ef0317118d2a1a6fc49aac65ffec7eb8087474158f42f26a639135216"},
@@ -704,8 +704,8 @@ files = [
 name = "msgpack"
 version = "1.0.4"
 description = "MessagePack serializer"
-category = "dev"
-optional = false
+category = "main"
+optional = true
 python-versions = "*"
 files = [
     {file = "msgpack-1.0.4-cp310-cp310-macosx_10_9_universal2.whl", hash = "sha256:4ab251d229d10498e9a2f3b1e68ef64cb393394ec477e3370c457f9430ce9250"},
@@ -805,8 +805,8 @@ testing = ["beautifulsoup4", "coverage[toml]", "pytest (>=6,<7)", "pytest-cov",
 name = "orjson"
 version = "3.8.5"
 description = "Fast, correct Python JSON library supporting dataclasses, datetimes, and numpy"
-category = "dev"
-optional = false
+category = "main"
+optional = true
 python-versions = ">=3.7"
 files = [
     {file = "orjson-3.8.5-cp310-cp310-macosx_10_7_x86_64.whl", hash = "sha256:143639b9898b094883481fac37733231da1c2ae3aec78a1dd8d3b58c9c9fceef"},
@@ -1019,8 +1019,8 @@ plugins = ["importlib-metadata"]
 name = "pymongo"
 version = "4.3.3"
 description = "Python driver for MongoDB <http://www.mongodb.org>"
-category = "dev"
-optional = false
+category = "main"
+optional = true
 python-versions = ">=3.7"
 files = [
     {file = "pymongo-4.3.3-cp310-cp310-macosx_10_9_universal2.whl", hash = "sha256:74731c9e423c93cbe791f60c27030b6af6a948cef67deca079da6cd1bb583a8e"},
@@ -1199,7 +1199,7 @@ files = [
 name = "pyyaml"
 version = "6.0"
 description = "YAML parser and emitter for Python"
-category = "dev"
+category = "main"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -1499,8 +1499,8 @@ files = [
 name = "tomlkit"
 version = "0.11.6"
 description = "Style preserving TOML library"
-category = "dev"
-optional = false
+category = "main"
+optional = true
 python-versions = ">=3.6"
 files = [
     {file = "tomlkit-0.11.6-py3-none-any.whl", hash = "sha256:07de26b0d8cfc18f871aec595fda24d95b08fef89d147caa861939f37230bf4b"},
@@ -1584,8 +1584,8 @@ files = [
 name = "ujson"
 version = "5.7.0"
 description = "Ultra fast JSON encoder and decoder for Python"
-category = "dev"
-optional = false
+category = "main"
+optional = true
 python-versions = ">=3.7"
 files = [
     {file = "ujson-5.7.0-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:5eba5e69e4361ac3a311cf44fa71bc619361b6e0626768a494771aacd1c2f09b"},
@@ -1710,7 +1710,16 @@ files = [
 docs = ["furo", "jaraco.packaging (>=9)", "jaraco.tidelift (>=1.4)", "rst.linker (>=1.9)", "sphinx (>=3.5)", "sphinx-lint"]
 testing = ["flake8 (<5)", "func-timeout", "jaraco.functools", "jaraco.itertools", "more-itertools", "pytest (>=6)", "pytest-black (>=0.3.7)", "pytest-checkdocs (>=2.4)", "pytest-cov", "pytest-enabler (>=1.3)", "pytest-flake8", "pytest-mypy (>=0.9.1)"]
 
+[extras]
+bson = ["pymongo"]
+cbor2 = ["cbor2"]
+msgpack = ["msgpack"]
+orjson = ["orjson"]
+pyyaml = ["PyYAML"]
+tomlkit = ["tomlkit"]
+ujson = ["ujson"]
+
 [metadata]
 lock-version = "2.0"
 python-versions = ">= 3.7"
-content-hash = "36e87de5c0e5f5132dd57bb68b48a1b6ab9b4fa174dc921be904fb692e332c77"
+content-hash = "dbfdd84b826b04d90a9360116cf5bf568c48e7450ec31847bd748fb2cac7e1c8"
diff --git a/pyproject.toml b/pyproject.toml
index 45afe235..8f64b1a3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,9 +25,24 @@ python = ">= 3.7"
 attrs = ">= 20"
 typing_extensions = { version = "*", python = "< 3.8" }
 exceptiongroup = { version = "*", python = "< 3.11" }
+ujson = { version = "^5.4.0", optional = true }
+orjson = { version = "^3.5.2", markers = "implementation_name == 'cpython'", optional = true }
+msgpack = { version = "^1.0.2", optional = true }
+PyYAML = { version = "^6.0", optional = true }
+tomlkit = { version = "^0.11.4", python = "<4", optional = true }
+cbor2 = { version = "^5.4.6", optional = true }
+pymongo = { version = "^4.2.0", optional = true }
+
+[tool.poetry.extras]
+ujson = ["ujson"]
+orjson = ["orjson"]
+msgpack = ["msgpack"]
+pyyaml = ["PyYAML"]
+tomlkit = ["tomlkit"]
+cbor2 = ["cbor2"]
+bson = ["pymongo"]
 
 [tool.poetry.group.dev.dependencies]
-pymongo = "^4.2.0"
 flake8 = {version = "^5.0.4", python = "^3.8"}
 tox = "^3.26.0"
 Sphinx = "^5.3.0"
@@ -38,17 +53,11 @@ pendulum = "^2.1.2"
 isort = { version = "5.10.1", python = "<4" }
 black = "^22.8.0"
 immutables = "^0.18"
-ujson = "^5.4.0"
-orjson = { version = "^3.5.2", markers = "implementation_name == 'cpython'" }
-msgpack = "^1.0.2"
-PyYAML = "^6.0"
-tomlkit = { version = "^0.11.4", python = "<4" }
 furo = "^2022.9.29"
 coverage = "^6.2"
 urllib3 = { version = "^1.26.12", python = "<4" }
 sphinx-copybutton = "^0.5.0"
 myst-parser = "^0.18.1"
-cbor2 = "^5.4.6"
 
 [tool.poetry.urls]
 "Changelog" = "https://catt.rs/en/latest/history.html"
@@ -77,4 +86,4 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.mypy]
 plugins = "unionize.py"
-strict = true
\ No newline at end of file
+strict = true
diff --git a/tox.ini b/tox.ini
index 1ff1d541..6a436f57 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,7 +33,7 @@ setenv =
 extras = dev
 allowlist_externals = poetry
 commands =
-    poetry install -v
+    poetry install -v --all-extras
     coverage run --source cattrs -m pytest tests {posargs}
 passenv = CI
 
@@ -44,7 +44,7 @@ setenv =
 extras = dev
 allowlist_externals = poetry
 commands =
-    poetry install -v
+    poetry install -v --all-extras
     coverage run --source cattrs -m pytest tests {posargs}
 passenv = CI