diff --git a/src/arg.c b/src/arg.c
index 52977b7..b31858d 100644
--- a/src/arg.c
+++ b/src/arg.c
@@ -206,8 +206,15 @@
 				goto parse_err;
 			break;
 
-		case ARGT_MSK6: /* not yet implemented */
-			goto not_impl;
+		case ARGT_MSK6:
+			if (in == beg)    // empty mask
+				goto empty_err;
+
+			if (!str2mask6(word, &arg->data.ipv6))
+				goto parse_err;
+
+			arg->type = ARGT_IPV6;
+			break;
 
 		case ARGT_TIME:
 			if (in == beg)    // empty time
diff --git a/src/hlua.c b/src/hlua.c
index fa629ba..ebe8c92 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -704,6 +704,13 @@
 			break;
 
 		case ARGT_MSK6:
+			memcpy(trash.str, argp[idx].data.str.str, argp[idx].data.str.len);
+			trash.str[argp[idx].data.str.len] = 0;
+			if (!str2mask6(trash.str, &argp[idx].data.ipv6))
+				WILL_LJMP(luaL_argerror(L, first + idx, "invalid IPv6 mask"));
+			argp[idx].type = ARGT_MSK6;
+			break;
+
 		case ARGT_MAP:
 		case ARGT_REG:
 		case ARGT_USR: