diff --git a/requirements.txt b/requirements.txt
index 4161aed..352b4d5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
-jupyter-book
+jupyter-book<2
 f90nml
 netCDF4
 numpy
-matplotlib
\ No newline at end of file
+matplotlib