diff --git a/tests/ci_build/conda_env/cpu_test.yml b/tests/ci_build/conda_env/cpu_test.yml
index 5a0a64245..c82125503 100644
--- a/tests/ci_build/conda_env/cpu_test.yml
+++ b/tests/ci_build/conda_env/cpu_test.yml
@@ -8,7 +8,7 @@ dependencies:
 - pyyaml
 - cpplint
 - pylint
-- numpy=1.19.4
+- numpy
 - scipy
 - scikit-learn
 - pandas