diff -u binutils-2.20.1/debian/rules binutils-2.20.1/debian/rules
--- binutils-2.20.1/debian/rules
+++ binutils-2.20.1/debian/rules
@@ -1034,6 +1034,18 @@
 ADDITIONAL_TARGETS = --enable-targets=s390-linux-gnu
 endif
 
+# During the opcodes cross-builds on amd64, configure tries running "as"
+# against the newly built libbfd which doesn't support x86-64; this is probably
+# because the newly built libs get prepended to the lib path; upstream suggests
+# using a different SONAME for libbfds with differing features, but this is
+# unpractical for us; the workaround below adds support for the build triplet
+# in the target libbfd, but this is a functional change over a natively built
+# binutils and should be fixed differently
+# see https://bugs.launchpad.net/ubuntu/+source/binutils/+bug/548451
+ifneq ($(DEB_BUILD_GNU_TYPE),$(DEB_HOST_GNU_TYPE))
+ADDITIONAL_TARGETS += --enable-targets=$(DEB_BUILD_GNU_TYPE)
+endif
+
 #-----------------------------------------------------------------
 # sysroot options
 ifdef WITH_SYSROOT