diff --git a/src/agents/extensions/visualization.py b/src/agents/extensions/visualization.py
index f607985..236bec9 100644
--- a/src/agents/extensions/visualization.py
+++ b/src/agents/extensions/visualization.py
@@ -1,6 +1,6 @@
 from typing import Optional
 
-import graphviz
+import graphviz  # type: ignore
 
 from agents import Agent
 from agents.handoffs import Handoff
diff --git a/tests/test_visualization.py b/tests/test_visualization.py
index 1f83d85..046cdd6 100644
--- a/tests/test_visualization.py
+++ b/tests/test_visualization.py
@@ -1,6 +1,6 @@
 from unittest.mock import Mock
 
-import graphviz
+import graphviz  # type: ignore
 import pytest
 
 from agents import Agent
diff --git a/uv.lock b/uv.lock
index d6eba43..3ee7f04 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1,4 +1,5 @@
 version = 1
+revision = 1
 requires-python = ">=3.9"
 resolution-markers = [
     "python_full_version >= '3.10'",
@@ -348,6 +349,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/f7/ec/67fbef5d497f86283db54c22eec6f6140243aae73265799baaaa19cd17fb/ghp_import-2.1.0-py3-none-any.whl", hash = "sha256:8337dd7b50877f163d4c0289bc1f1c7f127550241988d568c1db512c4324a619", size = 11034 },
 ]
 
+[[package]]
+name = "graphviz"
+version = "0.20.3"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/fa/83/5a40d19b8347f017e417710907f824915fba411a9befd092e52746b63e9f/graphviz-0.20.3.zip", hash = "sha256:09d6bc81e6a9fa392e7ba52135a9d49f1ed62526f96499325930e87ca1b5925d", size = 256455 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/00/be/d59db2d1d52697c6adc9eacaf50e8965b6345cc143f671e1ed068818d5cf/graphviz-0.20.3-py3-none-any.whl", hash = "sha256:81f848f2904515d8cd359cc611faba817598d2feaac4027b266aa3eda7b3dde5", size = 47126 },
+]
+
 [[package]]
 name = "greenlet"
 version = "3.1.1"
@@ -1090,6 +1100,9 @@ dependencies = [
 ]
 
 [package.optional-dependencies]
+viz = [
+    { name = "graphviz" },
+]
 voice = [
     { name = "numpy", version = "2.2.4", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
     { name = "websockets" },
@@ -1098,6 +1111,7 @@ voice = [
 [package.dev-dependencies]
 dev = [
     { name = "coverage" },
+    { name = "graphviz" },
     { name = "inline-snapshot" },
     { name = "mkdocs" },
     { name = "mkdocs-material" },
@@ -1118,6 +1132,7 @@ dev = [
 
 [package.metadata]
 requires-dist = [
+    { name = "graphviz", marker = "extra == 'viz'", specifier = ">=0.17" },
     { name = "griffe", specifier = ">=1.5.6,<2" },
     { name = "mcp", marker = "python_full_version >= '3.10'" },
     { name = "numpy", marker = "python_full_version >= '3.10' and extra == 'voice'", specifier = ">=2.2.0,<3" },
@@ -1128,10 +1143,12 @@ requires-dist = [
     { name = "typing-extensions", specifier = ">=4.12.2,<5" },
     { name = "websockets", marker = "extra == 'voice'", specifier = ">=15.0,<16" },
 ]
+provides-extras = ["voice", "viz"]
 
 [package.metadata.requires-dev]
 dev = [
     { name = "coverage", specifier = ">=7.6.12" },
+    { name = "graphviz" },
     { name = "inline-snapshot", specifier = ">=0.20.7" },
     { name = "mkdocs", specifier = ">=1.6.0" },
     { name = "mkdocs-material", specifier = ">=9.6.0" },