diff --git a/iam_units/currency.py b/iam_units/currency.py
index d7420f8..104c50e 100644
--- a/iam_units/currency.py
+++ b/iam_units/currency.py
@@ -4,13 +4,7 @@
 iam_units.update.currency.
 """
 
-from typing import Union
-
-try:
-    from typing import Literal
-except ImportError:
-    from typing_extensions import Literal  # type: ignore [assignment]
-
+from typing import Literal, Union
 
 #: Exchange rate data for method=EXC, period=2005, from
 #: https://data.oecd.org/conversion/exchange-rates.htm
diff --git a/pyproject.toml b/pyproject.toml
index 65bd856..d630e92 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,7 +17,6 @@ classifiers = [
   "Operating System :: OS Independent",
   "Programming Language :: Python",
   "Programming Language :: Python :: 3",
-  "Programming Language :: Python :: 3.7",
   "Programming Language :: Python :: 3.8",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
@@ -26,7 +25,7 @@ classifiers = [
   "Topic :: Scientific/Engineering",
   "Topic :: Scientific/Engineering :: Information Analysis",
 ]
-dependencies = ["pint >= 0.11", "typing_extensions; python_version < '3.8'"]
+dependencies = ["pint >= 0.11"]
 
 [project.urls]
 homepage = "https://github.com/IAMconsortium/units"