Door sensor not staying stuck to Steel front door

[Nick117]

I have been enjoying my 2 new ooma door sensors, but one of my sensors will not stay stuck to my steel front door and has been causing a "tamper" alert within 24-48 hours after applying the sensor using the included 3M command strips. Unfortunately I have now gone through all of the included strips and it looks like this security solution may not work for me. I have tried cleaning the surface, etc, but it looks like the issue may be the steel door itself.

Has anyone been able to successfully attach the sensor to a steel door or have any other suggestions on resolving this issue?

Thanks in advance.

[sabretooth02]

A drop of Super Glue?

[thomasm]

A hole or two in the door and one or two sheet metal screws?