diff --git a/requirements.txt b/requirements.txt
index 6ddd34f..2e0eed9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 numpy
-cupy
-chainer
-librosa
+cupy<6.0.0
+chainer<6.0.0
+librosa<0.7.0
 pysptk
 pyworld
 fastdtw