diff --git a/index.js b/index.js
index ea267c8..566df88 100644
--- a/index.js
+++ b/index.js
@@ -8,11 +8,12 @@ function shift (stream) {
 
 function getStateLength (state) {
   if (state.buffer.length) {
+    var idx = state.bufferIndex || 0
     // Since node 6.3.0 state.buffer is a BufferList not an array
     if (state.buffer.head) {
       return state.buffer.head.data.length
-    } else if (state.buffer.length > 0 && state.buffer[0]) {
-      return state.buffer[0].length
+    } else if (state.buffer.length - idx > 0 && state.buffer[idx]) {
+      return state.buffer[idx].length
     }
   }