diff --git a/doc/todo.rst b/doc/todo.rst
index 99440e52a..3a3d4d5ba 100644
--- a/doc/todo.rst
+++ b/doc/todo.rst
@@ -15,3 +15,8 @@ New methods
 * AIIKNN_: Garcia, Salvador, et al. "Prototype selection for nearest neighbor classification: Taxonomy and empirical study." IEEE Transactions on Pattern Analysis and Machine Intelligence 34.3 (2012): 417-435.
 
 .. _AIIKNN: https://www.semanticscholar.org/paper/Prototype-Selection-for-Nearest-Neighbor-Garc%C3%ADa-Derrac/fbca1824c49e02da37e5e780eaf0ab6ddfaf5614/pdf
+
+API improvements
+~~~~~~~~~~~~~~~~
+
+* Remove `npy` files in the testting and perform toy tests instead.