diff --git a/readthedocs.yml b/readthedocs.yml
index 253ea14..53e3b51 100644
--- a/readthedocs.yml
+++ b/readthedocs.yml
@@ -10,8 +10,8 @@ build:
     post_create_environment:
       - "pip install numpy cython pysam"
     pre_build:
-      - python -c "import pairtools.lib.dedup_cython"
       - "pip install --upgrade numpy"
+      - python setup.py build
       - python -c "import pairtools.lib.dedup_cython"
 
 sphinx: