diff --git a/configure.ac b/configure.ac
index 1a5051a..e7c99b0 100755
--- a/configure.ac
+++ b/configure.ac
@@ -782,15 +782,18 @@
 dnl --------------------------
 dnl Determine IS-IS I/O method
 dnl --------------------------
+AC_DEFINE(ISIS_METHOD_PFPACKET,	1, [ constant value for isis method pfpacket ])
+AC_DEFINE(ISIS_METHOD_DLPI,	2, [ constant value for isis method dlpi ])
+AC_DEFINE(ISIS_METHOD_BPF,	3, [ constant value for isis method bpf ])
 AC_CHECK_HEADER(net/bpf.h)
 AC_CHECK_HEADER(sys/dlpi.h)
 AC_MSG_CHECKING(zebra IS-IS I/O method)
 if test x"$opsys" = x"gnu-linux"; then
   AC_MSG_RESULT(pfpacket)
-  ISIS_METHOD=isis_pfpacket.o
+  ISIS_METHOD_MACRO="ISIS_METHOD_PFPACKET"
 elif test x"$opsys" = x"sol2-6" -o x"$opsys" = x"sol8"; then
   AC_MSG_RESULT(DLPI)
-  ISIS_METHOD="isis_dlpi.o"
+  ISIS_METHOD_MACRO="ISIS_METHOD_DLPI"
 else
   if test $ac_cv_header_net_bpf_h = no; then
     if test $ac_cv_header_sys_dlpi_h = no; then
@@ -800,13 +803,13 @@
     else
       AC_MSG_RESULT(DLPI)
     fi
-    ISIS_METHOD="isis_dlpi.o"
+    ISIS_METHOD_MACRO="ISIS_METHOD_DLPI"
   else
     AC_MSG_RESULT(BPF)
-    ISIS_METHOD="isis_bpf.o"
+    ISIS_METHOD_MACRO="ISIS_METHOD_BPF"
   fi
 fi
-AC_SUBST(ISIS_METHOD)
+AC_DEFINE_UNQUOTED(ISIS_METHOD, $ISIS_METHOD_MACRO, [ selected method for isis, == one of the constants ])
 
 dnl ------------------------------------
 dnl check for broken CMSG_FIRSTHDR macro
diff --git a/isisd/Makefile.am b/isisd/Makefile.am
index 9c30339..26b8ee7 100644
--- a/isisd/Makefile.am
+++ b/isisd/Makefile.am
@@ -13,8 +13,6 @@
 sbin_PROGRAMS = isisd 
 SUBDIRS = topology
 
-isis_method = @ISIS_METHOD@
-
 libisis_a_SOURCES = \
 	isis_adjacency.c isis_lsp.c dict.c isis_circuit.c isis_pdu.c \
 	isis_tlv.c isisd.c isis_misc.c isis_zebra.c isis_dr.c \
@@ -30,13 +28,10 @@
 	include-netbsd/clnp.h include-netbsd/esis.h include-netbsd/iso.h
 
 isisd_SOURCES = \
-	isis_main.c $(libisis_a_SOURCES)
+	isis_main.c $(libisis_a_SOURCES) \
+	isis_bpf.c isis_dlpi.c isis_pfpacket.c
 
-isisd_LDADD = $(isis_method) @ISIS_TOPOLOGY_LIB@ ../lib/libzebra.la @LIBCAP@
-
-isisd_DEPENDENCIES = $(isis_method)
-
-EXTRA_DIST = isis_bpf.c isis_dlpi.c isis_pfpacket.c
+isisd_LDADD = @ISIS_TOPOLOGY_LIB@ ../lib/libzebra.la @LIBCAP@
 
 examplesdir = $(exampledir)
 dist_examples_DATA = isisd.conf.sample
diff --git a/isisd/isis_bpf.c b/isisd/isis_bpf.c
index 8c3602d..05f1138 100644
--- a/isisd/isis_bpf.c
+++ b/isisd/isis_bpf.c
@@ -21,6 +21,7 @@
  */
 
 #include <zebra.h>
+#if ISIS_METHOD == ISIS_METHOD_BPF
 #include <net/if.h>
 #include <netinet/if_ether.h>
 #include <sys/time.h>
@@ -339,3 +340,5 @@
 {
   return ISIS_OK;
 }
+
+#endif /* ISIS_METHOD == ISIS_METHOD_BPF */
diff --git a/isisd/isis_dlpi.c b/isisd/isis_dlpi.c
index 3cbe0b4..fe872a9 100644
--- a/isisd/isis_dlpi.c
+++ b/isisd/isis_dlpi.c
@@ -21,6 +21,7 @@
  */
 
 #include <zebra.h>
+#if ISIS_METHOD == ISIS_METHOD_DLPI
 #include <net/if.h>
 #include <netinet/if_ether.h>
 #include <sys/types.h>
@@ -622,3 +623,5 @@
     sock_buff, stream_get_endp (circuit->snd_stream) + LLC_LEN, 0);
   return ISIS_OK;
 }
+
+#endif /* ISIS_METHOD == ISIS_METHOD_DLPI */
diff --git a/isisd/isis_pfpacket.c b/isisd/isis_pfpacket.c
index 8752dba..9e4165e 100644
--- a/isisd/isis_pfpacket.c
+++ b/isisd/isis_pfpacket.c
@@ -21,6 +21,7 @@
  */
 
 #include <zebra.h>
+#if ISIS_METHOD == ISIS_METHOD_PFPACKET
 #include <net/ethernet.h>	/* the L2 protocols */
 #include <netpacket/packet.h>
 
@@ -371,3 +372,5 @@
 
   return ISIS_OK;
 }
+
+#endif /* ISIS_METHOD == ISIS_METHOD_PFPACKET */