diff --git a/pure-parser.js b/pure-parser.js
index ddf696b..4896362 100644
--- a/pure-parser.js
+++ b/pure-parser.js
@@ -57,6 +57,12 @@ pdns.unpackQname = function (ui8) {
 
   do {
     len = ui8[total];
+    if (0xc0 === len) {
+      throw new Error("discovered a compression pointer at byte " + total
+        + " pointing to byte " + ui8[total + 1]
+        + ", but compression pointer support is not yet implemented"
+      );
+    }
     //str.length = 0; // fast empty array
     if (ui8.byteLength - total < len) {
       throw new Error(