diff -up ./configure.ac.orig ./configure.ac
--- ./configure.ac.orig	2011-09-24 12:19:04.267267063 +0000
+++ ./configure.ac	2011-09-24 12:19:23.661890009 +0000
@@ -118,7 +118,7 @@ if test -z "$have_gpgme"; then
 	AC_MSG_ERROR(GPGME $min_gpgme_version or later needed)
 fi
 
-SEAHORSE_CFLAGS="$SEAHORSE_CFLAGS $GPGME_CFLAGS"
+SEAHORSE_CFLAGS="$SEAHORSE_CFLAGS $GPGME_CFLAGS -D_FILE_OFFSET_BITS=64"
 SEAHORSE_LIBS="$SEAHORSE_LIBS $GPGME_LIBS"
 
 dnl ****************************************************************************