diff --git a/filter/f-inst.c b/filter/f-inst.c
index c56d874b..510c431f 100644
--- a/filter/f-inst.c
+++ b/filter/f-inst.c
@@ -869,10 +869,6 @@
 	l->attrs[0].u.data = v1.val.i;
 	break;
 
-      case EAF_TYPE_OPAQUE:
-	runtime( "Setting opaque attribute is not allowed" );
-	break;
-
       case EAF_TYPE_IP_ADDRESS:;
 	int len = sizeof(ip_addr);
 	struct adata *ad = lp_alloc(fs->pool, sizeof(struct adata) + len);
@@ -881,6 +877,7 @@
 	l->attrs[0].u.ptr = ad;
 	break;
 
+      case EAF_TYPE_OPAQUE:
       case EAF_TYPE_AS_PATH:
       case EAF_TYPE_INT_SET:
       case EAF_TYPE_EC_SET:
diff --git a/filter/f-util.c b/filter/f-util.c
index d589927a..a47a8747 100644
--- a/filter/f-util.c
+++ b/filter/f-util.c
@@ -294,6 +294,9 @@ ca_lookup(pool *p, const char *name, int f_type)
     case T_LCLIST:
       ea_type = EAF_TYPE_LC_SET;
       break;
+    case T_BYTESTRING:
+      ea_type = EAF_TYPE_OPAQUE;
+      break;
     default:
       cf_error("Custom route attribute of unsupported type");
   }