diff --git a/tutorials/05_services.md b/tutorials/05_services.md
index da4e0e955..6ba56977a 100644
--- a/tutorials/05_services.md
+++ b/tutorials/05_services.md
@@ -12,7 +12,7 @@ service consumer. A service provider is the node that offers the service to the
 rest of the world. The service consumers are the nodes that request the function
 offered by the provider. Note that in Gazebo Transport the location of the
 service is hidden. The discovery layer of the library is in charge of
-discovering and keeping and updated list of services available.
+discovering and keeping an updated list of services available.
 
 In the next tutorial, one node will be the service provider that offers an
 *echo* service, whereas the other node will be the service consumer requesting