https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68319
--- Comment #1 from Gerhard Steinmetz <gerhard.steinmetz.fort...@t-online.de> --- Same issue with interface of a function. Compiles if interface is effectivly not used : $ cat z1x.f90 module m interface subroutine s entry e end end interface contains subroutine g end end $ gfortran -g -O0 -Wall -fcheck=all -c z1x.f90