Index: gmp-4.2.4/Makefile.am
===================================================================
--- gmp-4.2.4.orig/Makefile.am	2008-09-10 19:31:27.000000000 +0000
+++ gmp-4.2.4/Makefile.am	2009-07-06 20:19:19.000000000 +0000
@@ -106,7 +106,7 @@
 # but anyone knowledgable enough to be playing with exec_prefix will be able
 # to address that.
 #
-includeexecdir = $(exec_prefix)/include
+includeexecdir = $(includedir)
 include_HEADERS = $(GMPXX_HEADERS_OPTION)
 nodist_includeexec_HEADERS = gmp.h $(MPBSD_HEADERS_OPTION)
 lib_LTLIBRARIES = libgmp.la $(GMPXX_LTLIBRARIES_OPTION) $(MPBSD_LTLIBRARIES_OPTION)