diff --git a/.pre-commit-hooks.yaml b/.pre-commit-hooks.yaml
index 97b473c..22c0a48 100644
--- a/.pre-commit-hooks.yaml
+++ b/.pre-commit-hooks.yaml
@@ -4,6 +4,7 @@
     language: python
     entry: optimize-avif
     types: [avif]
+    additional_dependencies: [".[avif]"]
 
   - id: optimize-jpg
     name: optimize jpgs
@@ -25,6 +26,7 @@
     language: python
     entry: optimize-svg
     types: [svg]
+    additional_dependencies: [".[svg]"]
 
   - id: optimize-webp
     name: optimize webps
diff --git a/Makefile b/Makefile
index 9494e66..72ddec3 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@ $(VENV)/$(MARKER): $(VENV)
 ## venv          : Initialize virtual environment with dependencies.
 .PHONY: venv
 venv: $(VENV)/$(MARKER)
-	$(VENV)/pip install -q .[tests]
+	$(VENV)/pip install -q .[tests,svg,avif]
 
 
 .PHONY: all
diff --git a/pre_commit_images/optimize_avif.py b/pre_commit_images/optimize_avif.py
index b4efe77..151f871 100755
--- a/pre_commit_images/optimize_avif.py
+++ b/pre_commit_images/optimize_avif.py
@@ -7,11 +7,16 @@
 from typing import IO
 from typing import Optional
 
-import pillow_avif  # noqa: F401
 from PIL import Image
 
 from .optimizer import _optimize_images
 
+try:
+    import pillow_avif  # noqa: F401
+except ImportError:
+    warnings.warn('Missing `pillow_avif` dependency, install optional "[avif]" dependency group')
+    sys.exit(1)
+
 
 def main(argv: Optional[Sequence[str]] = None) -> int:
     parser = argparse.ArgumentParser()
diff --git a/pre_commit_images/optimize_svg.py b/pre_commit_images/optimize_svg.py
index a8b5bce..befa828 100755
--- a/pre_commit_images/optimize_svg.py
+++ b/pre_commit_images/optimize_svg.py
@@ -1,15 +1,20 @@
 #!/usr/bin/env python3
 import argparse
+import pathlib
 import sys
+import warnings
 from collections.abc import Sequence
-from pathlib import Path
 from typing import IO
 from typing import Optional
 
-from scour import scour
-
 from .optimizer import _optimize_images
 
+try:
+    from scour import scour
+except ImportError:
+    warnings.warn('Missing `scour` dependency, install optional "[svg]" dependency group')
+    sys.exit(1)
+
 
 def main(argv: Optional[Sequence[str]] = None) -> int:
     parser = argparse.ArgumentParser()
@@ -23,7 +28,7 @@ def main(argv: Optional[Sequence[str]] = None) -> int:
     )
     args = parser.parse_args(argv)
 
-    def optimize(source: Path, target: IO[bytes]) -> None:
+    def optimize(source: pathlib.Path, target: IO[bytes]) -> None:
         data = source.read_text(encoding="utf-8")
         options = {
             "enable_viewboxing": True,
diff --git a/pyproject.toml b/pyproject.toml
index 0c0e4c4..e897149 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,11 +22,15 @@ classifiers = [
 requires-python = ">=3.9"
 dependencies = [
     "pillow==10.0.1",
-    "pillow-avif-plugin==1.4.1",
-    "scour==0.38.2",
 ]
 
 [project.optional-dependencies]
+avif = [
+    "pillow-avif-plugin==1.4.1",
+]
+svg = [
+    "scour==0.38.2",
+]
 dev = [
     "pre-commit",
     "ruff",
diff --git a/tox.ini b/tox.ini
index 28bb51f..6d52342 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,7 +3,7 @@ envlist  = py39,py310,py311,py312,pre-commit
 isolated_build = True
 
 [testenv]
-extras   = tests
+extras   = tests,svg,avif
 commands =
   pytest {posargs:tests}
 
@@ -13,6 +13,6 @@ deps     = pre-commit
 commands = pre-commit run --all-files
 
 [testenv:static]
-extras   = tests
+extras   = tests,svg,avif
 commands =
   pytest --ignore tests