# Upgrade Version 9 to 9.1


## Meter source name change

In NServiceBus 9.0.x, the OpenTelemetry meter source name was `NServiceBus.Core`. In NServiceBus 9.1.0, it has been changed to `NServiceBus.Core.Pipeline.Incoming`.

Update endpoint configuration code to use the new meter source name or use a wildcard notation, e.g., `NServiceBus.Core*`.