diff --git a/scripts/targets-ipv6-multicast-echo.nse b/scripts/targets-ipv6-multicast-echo.nse
index b2cb22336..dfab2fde5 100644
--- a/scripts/targets-ipv6-multicast-echo.nse
+++ b/scripts/targets-ipv6-multicast-echo.nse
@@ -25,8 +25,7 @@ require 'packet'
 local bit = require 'bit'
 
 prerule = function()
-	return nmap.is_privileged() and
-		(stdnse.get_script_args(SCRIPT_NAME .. ".interface") or nmap.get_interface())
+	return nmap.is_privileged()
 end
 
 catch = function()
@@ -41,6 +40,11 @@ end
 
 action = function()
 	local if_name = stdnse.get_script_args(SCRIPT_NAME .. ".interface") or nmap.get_interface()
+	if not if_name then
+		return "Error: need an interface name.\n"
+			.. "Use -e <iface> or --script-args " .. SCRIPT_NAME .. ".interface=<iface>."
+	end
+
 	local if_nfo, err = nmap.get_interface_info(if_name)
 	if not if_nfo then
 		stdnse.print_debug(err)
diff --git a/scripts/targets-ipv6-multicast-invalid-dst.nse b/scripts/targets-ipv6-multicast-invalid-dst.nse
index 9707d4fb1..047dd82bd 100644
--- a/scripts/targets-ipv6-multicast-invalid-dst.nse
+++ b/scripts/targets-ipv6-multicast-invalid-dst.nse
@@ -26,8 +26,7 @@ require 'packet'
 local bit = require 'bit'
 
 prerule = function()
-	return nmap.is_privileged() and
-		(stdnse.get_script_args(SCRIPT_NAME .. ".interface") or nmap.get_interface())
+	return nmap.is_privileged()
 end
 
 catch = function()
@@ -58,6 +57,11 @@ end
 
 action = function()
 	local if_name = stdnse.get_script_args(SCRIPT_NAME .. ".interface") or nmap.get_interface()
+	if not if_name then
+		return "Error: need an interface name.\n"
+			.. "Use -e <iface> or --script-args " .. SCRIPT_NAME .. ".interface=<iface>."
+	end
+
 	local if_nfo, err = nmap.get_interface_info(if_name)
 	if not if_nfo then
 		stdnse.print_debug(err)
diff --git a/scripts/targets-ipv6-multicast-slaac.nse b/scripts/targets-ipv6-multicast-slaac.nse
index 7152fe9e2..a7516a0bf 100644
--- a/scripts/targets-ipv6-multicast-slaac.nse
+++ b/scripts/targets-ipv6-multicast-slaac.nse
@@ -36,8 +36,7 @@ require "os"
 require "math"
 
 prerule = function()
-	return nmap.is_privileged() and
-		(stdnse.get_script_args(SCRIPT_NAME .. ".interface") or nmap.get_interface())
+	return nmap.is_privileged()
 end
 
 catch = function()
@@ -92,6 +91,11 @@ end
 
 action = function()
 	local if_name = stdnse.get_script_args(SCRIPT_NAME .. ".interface") or nmap.get_interface()
+	if not if_name then
+		return "Error: need an interface name.\n"
+			.. "Use -e <iface> or --script-args " .. SCRIPT_NAME .. ".interface=<iface>."
+	end
+
 	local if_nfo, err = nmap.get_interface_info(if_name)
 	if not if_nfo then
 		stdnse.print_debug(err)