diff --git a/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env.yml b/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env.yml
index 554e53fe..408755fb 100644
--- a/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env.yml
+++ b/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env.yml
@@ -7,6 +7,7 @@ dependencies:
 - nb_conda
 - cython
 - urllib3<1.24
+- numpy==1.18.5
 
 - pip:
   # Required packages for AzureML execution, history, and data preparation.
diff --git a/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env_mac.yml b/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env_mac.yml
index 64e0820c..f20a4e27 100644
--- a/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env_mac.yml
+++ b/how-to-use-azureml/automated-machine-learning/experimental/automl_thin_client_env_mac.yml
@@ -8,6 +8,7 @@ dependencies:
 - nb_conda
 - cython
 - urllib3<1.24
+- numpy==1.18.5
 
 - pip:
   # Required packages for AzureML execution, history, and data preparation.