diff --git a/pyproject.toml b/pyproject.toml
index 5034b50e..11e3dbfa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ include = ["src/pfun/py.typed", "src/pfun/*.c"]
 
 [tool.poetry.dependencies]
 python = ">= 3.7, < 3.11"
-typing-extensions = "^3.10.0.0"
+typing-extensions = ">= 4.0.0, < 5.0.0"
 aiohttp = {extras = ["speedups"], version = "^3.7.4", optional = true}
 asyncpg = {version = "^0.23.0", optional = true}
 hypothesis = {version = "^6.8.5", optional = true}