https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66575
--- Comment #1 from Gerhard Steinmetz <gerhard.steinmetz.fort...@t-online.de> --- The above sources can be reduced further. The part below "contains" (inclusive contains) is not needed to produce the effect : $ cat zlcti_4.f90 module m interface operator (.f.) procedure f interface operator (.g.) procedure g end interface end $ cat zlcti_6.f90 module m interface operator (.f.) procedure f end interface operator (.g.) procedure g end