diff --git a/tools/internal_ci/linux/grpc_portability_build_only.sh b/tools/internal_ci/linux/grpc_portability_build_only.sh
index 9fac5bcac07..ebdc0e82d76 100644
--- a/tools/internal_ci/linux/grpc_portability_build_only.sh
+++ b/tools/internal_ci/linux/grpc_portability_build_only.sh
@@ -35,4 +35,7 @@ cd $(dirname $0)/../../..
 
 git submodule update --init
 
+# download docker images from dockerhub
+export DOCKERHUB_ORGANIZATION=grpctesting
+
 tools/jenkins/run_jenkins_matrix.sh -f portability linux --build_only