https://bugs.gentoo.org/927863

--- a/configure.ac
+++ b/configure.ac
@@ -102,7 +102,7 @@
 PPACKAGE=`echo "${PACKAGE}" | "$SED" -e "${transform}"`
 FVWM_MODULESUBDIR=/${PPACKAGE}/${VERSION}
 FVWM_DATASUBDIR=/${PPACKAGE}
-FVWM_DOCSUBDIR=/doc/${PPACKAGE}
+FVWM_DOCSUBDIR=/doc/${PF}
 
 AC_ARG_ENABLE(package-subdirs,
   AS_HELP_STRING([--disable-package-subdirs],
