diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
index 0a523d1028d..fca485d2a18 100644
--- a/lib/matplotlib/transforms.py
+++ b/lib/matplotlib/transforms.py
@@ -2024,7 +2024,7 @@ def _get_is_separable(self):
 
 class IdentityTransform(Affine2DBase):
     """
-    A special class that does on thing, the identity transform, in a
+    A special class that does one thing, the identity transform, in a
     fast way.
     """
     _mtx = np.identity(3)