diff --git a/pyproject.toml b/pyproject.toml
index 5f69907..00a47d1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,7 +12,7 @@ repository = "https://github.com/kojiishi/east_asian_spacing"
 license = "Apache-2.0"
 
 [tool.poetry.dependencies]
-python = ">=3.7"
+python = ">=3.8"
 fonttools = {version = ">=4.13.0", extras = ["woff"]}
 uharfbuzz = ">=0.17"
 
diff --git a/tox.ini b/tox.ini
index 98f62c0..8beaf2c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py3{7,8,9,10}
+envlist = py3{8,9,10,11}
 # Set "isolated_build" to use "pyproject.toml".
 isolated_build = True
 # "isolated_build" requires 3.3.0.