diff --git a/configure.in b/configure.in
index 81926a9bf7..2e9aa7b684 100644
--- a/configure.in
+++ b/configure.in
@@ -13,7 +13,7 @@ dnl PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 dnl ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 dnl SOFTWARE.
 
-AC_REVISION($Revision: 1.48 $)
+AC_REVISION($Revision: 1.49 $)
 
 AC_PREREQ(2.13)
 
@@ -317,8 +317,8 @@ AC_TRY_COMPILE([
 	[AC_MSG_RESULT(no)
 	ISC_NET_HAVEIPV6="#undef ISC_NET_HAVEIPV6"
 	ISC_IPV6_H="ipv6.h"
-	ISC_IPV6_O="ipv6.o"
-	ISC_ISCIPV6_O="unix/ipv6.o"
+	ISC_IPV6_O="ipv6.$O"
+	ISC_ISCIPV6_O="unix/ipv6.$O"
 	ISC_IPV6_C="ipv6.c"])
 AC_SUBST(ISC_NET_HAVEIPV6)
 AC_SUBST(ISC_IPV6_H)