diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
index 74a73725d5d9..ce7d302ae9e7 100644
--- a/lib/matplotlib/pyplot.py
+++ b/lib/matplotlib/pyplot.py
@@ -479,7 +479,7 @@ def draw_if_interactive(*args, **kwargs):
 
 
 # This function's signature is rewritten upon backend-load by switch_backend.
-def show(*args, **kwargs):
+def show(*args, **kwargs) -> None:
     """
     Display all open figures.