Index: libffi-3.0.9/libffi.pc.in
===================================================================
--- libffi-3.0.9.orig/libffi.pc.in
+++ libffi-3.0.9/libffi.pc.in
@@ -1,7 +1,7 @@
 prefix=@prefix@
 exec_prefix=@exec_prefix@
 libdir=@libdir@
-includedir=${libdir}/@PACKAGE_NAME@-@PACKAGE_VERSION@/include
+includedir=@includedir@
 
 Name: @PACKAGE_NAME@
 Description: Library supporting Foreign Function Interfaces
Index: libffi-3.0.9/include/Makefile.am
===================================================================
--- libffi-3.0.9.orig/include/Makefile.am
+++ libffi-3.0.9/include/Makefile.am
@@ -5,5 +5,5 @@ AUTOMAKE_OPTIONS=foreign
 DISTCLEANFILES=ffitarget.h
 EXTRA_DIST=ffi.h.in ffi_common.h
 
-includesdir = $(libdir)/@PACKAGE_NAME@-@PACKAGE_VERSION@/include
+includesdir = $(prefix)/include
 nodist_includes_HEADERS = ffi.h ffitarget.h