p4merge no longer working after upgrade to 2.26.0

Dear git community,

I recently upgraded to git 2.26.0 and this broke my merge/difftool p4merge.

This is my config with regards to the mergetool

merge.tool=p4merge mergetool.p4merge.path=/opt/perforce/bin/p4merge mergetool.p4merge.prompt=false

and this is the error message I am getting. Funnily enough p4merge is mentioned in the alternatives

git config option merge.tool set to unknown tool: p4merge Resetting to default...This message is displayed because 'merge.tool' is not configured. See 'git mergetool --tool-help' or 'git help config' for more details. 'git mergetool' will now attempt to use one of the following tools: opendiff kdiff3 tkdiff xxdiff meld tortoisemerge gvimdiff diffuse diffmerge ecmerge p4merge araxis bc codecompare smerge emerge vimdiff

Colleagues of mine reported that it is still working in 2.25.4

Kind regards

Lars Fricke