diff --git a/requests/utils.py b/requests/utils.py
index f49d8215..727dc267 100644
--- a/requests/utils.py
+++ b/requests/utils.py
@@ -497,7 +497,7 @@ def requote_uri(uri):
 
 
 def address_in_network(ip, net):
-    """This function allows you to check if on IP belongs to a network subnet
+    """This function allows you to check if an IP belongs to a network subnet
 
     Example: returns True if ip = 192.168.1.1 and net = 192.168.1.0/24
              returns False if ip = 192.168.1.1 and net = 192.168.100.0/24