diff --git a/pyproject.toml b/pyproject.toml
index 4843c429..539832ac 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,7 @@ diagrams="diagrams.cli:main"
 
 [tool.poetry.dependencies]
 python = "^3.9"
-graphviz = ">=0.13.2,<0.21.0"
+graphviz = ">=0.13.2,<0.22.0"
 jinja2 = ">=2.10,<4.0"
 typed-ast = {version="^1.5.5", markers="python_version<'3.8'"}