diff --git a/pyproject.toml b/pyproject.toml
index a4babf6..9705042 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -27,6 +27,7 @@ requires-python = ">=3.6"
 requires = [
     "numpy",
     "matplotlib",
+    "pint",
     "scipy",    
 ]
 
diff --git a/src/skaero/__init__.py b/src/skaero/__init__.py
index 4018e96..1975004 100644
--- a/src/skaero/__init__.py
+++ b/src/skaero/__init__.py
@@ -7,4 +7,10 @@
 
 """
 
+# Package version
 __version__ = "0.2.dev0"
+
+# Prellocate units module
+import pint
+
+units = pint.UnitRegistry()