diff --git a/ci/requirements-3.6.build b/ci/requirements-3.6.build
index 1c4b46aea3865..31ffd5acc7fcc 100644
--- a/ci/requirements-3.6.build
+++ b/ci/requirements-3.6.build
@@ -2,5 +2,7 @@ python=3.6*
 python-dateutil
 pytz
 nomkl
-numpy
 cython
+
+# pin numpy that is built for all our deps
+numpy=1.13.1=py36_blas_openblas_201