diff --git a/Dockerfile b/Dockerfile
index 2db8c7a..245fb46 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM rocker/tidyverse
+FROM rocker/tidyverse:4.1.2
 MAINTAINER Marc A. Suchard <msuchard@ucla.edu>
 
 RUN apt-get update && apt-get install -y python-dev openjdk-8-jdk liblzma-dev libbz2-dev \
@@ -24,9 +24,9 @@ RUN installGithub.r \
 	OHDSI/FeatureExtraction \
 	OHDSI/BigKnn \
 	OHDSI/PatientLevelPrediction \
-	OHDSI/CohortMethod \
+	OHDSI/CohortMethod 
 	OHDSI/PublicOracle \
-	hadley/xml2 \
+	r-lib/xml2 \
 	cloudyr/aws.s3 \
 	OHDSI/OhdsiSharing \
 && rm -rf /tmp/downloaded_packages/ /tmp/*.rds