diff --git a/debian/rules b/debian/rules
index e20789a..0a42fcc 100755
--- a/debian/rules
+++ b/debian/rules
@@ -3,8 +3,8 @@
 	dh $@
 
 DEB_HOST_ARCH := $(shell dpkg-architecture -qDEB_HOST_ARCH)
-DEB_BUILD_GNU_TYPE := $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
-DEB_HOST_GNU_TYPE := $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
+DEB_BUILD_GNU_TYPE ?= $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
+DEB_HOST_GNU_TYPE ?= $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
 
 ifeq ($(DEB_BUILD_GNU_TYPE),$(DEB_HOST_GNU_TYPE))
 CROSS :=