diff --git a/datok.go b/datok.go
index 5bd54e9..5191877 100644
--- a/datok.go
+++ b/datok.go
@@ -968,6 +968,7 @@
 			}
 
 			// TODO: Better as a ring buffer
+			// buffer = buffer[buffc:] !slower
 			for x, i := range buffer[buffc:buffi] {
 				buffer[x] = i
 			}
diff --git a/datok_test.go b/datok_test.go
index 9e0d9a6..13b1a7c 100644
--- a/datok_test.go
+++ b/datok_test.go
@@ -1067,3 +1067,8 @@
 //   BenchmarkDoubleArrayConstruction-4         74510             15879 ns/op           10703 B/op         29 allocs/op
 //   BenchmarkDoubleArrayLarger-4                  18          73752383 ns/op         6357956 B/op       2579 allocs/op
 //   BenchmarkMatrixTransduce-4                 46870             27140 ns/op           12408 B/op          6 allocs/op
+// 2021-10-28 - Finalize feature compatibility with KorAP-Tokenizer
+//   BenchmarkDoubleArrayTransduce-4            39130             31612 ns/op           28944 B/op         16 allocs/op
+//   BenchmarkDoubleArrayConstruction-4         79302             14994 ns/op           10703 B/op         29 allocs/op
+//   BenchmarkDoubleArrayLarger-4                  18          67942077 ns/op         6357870 B/op       2577 allocs/op
+//   BenchmarkMatrixTransduce-4                 39536             30510 ns/op           28944 B/op         16 allocs/op
diff --git a/matrix.go b/matrix.go
index 021c191..7141e74 100644
--- a/matrix.go
+++ b/matrix.go
@@ -521,6 +521,7 @@
 			}
 
 			// TODO: Better as a ring buffer
+			// buffer = buffer[buffc:]
 			for x, i := range buffer[buffc:buffi] {
 				buffer[x] = i
 			}