Repair plastic pipe?

Hello
I accidentally put a smallcut/nick into a semi flexible underfloor water pipe which feeds one of the radiators in my home, the pipe is white in colour and I think it is 15mm diameter.
It is not leaking (yet) but I need to get piece of mind by patching/strengthening it in some way.

Any advice would be appreciated.

Thank You

Kevin

Kevin
September 2010