diff --git a/configure.ac b/configure.ac
index f8ac1ab..12c3faa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -68,6 +68,18 @@ echo "nanosleep() required for timing operations."
 exit 1
 ])
 
+# On illumos we need -lsocket
+AC_SEARCH_LIBS(socket, [socket], [], [
+echo "socket()"
+exit 1
+])
+
+# On illumos inet_ntop in in -lnsl
+AC_SEARCH_LIBS(inet_ntop, [nsl], [], [
+echo "inet_ntop()"
+exit 1
+])
+
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
 
diff --git a/src/portable_endian.h b/src/portable_endian.h
index 520c79a..c7cb852 100644
--- a/src/portable_endian.h
+++ b/src/portable_endian.h
@@ -55,7 +55,7 @@
 
 #	include <sys/endian.h>
 
-#elif defined(__SunOS)
+#elif defined(__sun) && defined(__SVR4)
 
 #	include <sys/types.h>
 #	include <netinet/in.h>