diff --git a/tools/dockerfile/grpc_interop_node/build_interop.sh b/tools/dockerfile/grpc_interop_node/build_interop.sh
index 4d4290d0b4112671f7d32d8971c6169169be7c7b..b99fd444eeadfce07819a60d1cd752fc3054953f 100755
--- a/tools/dockerfile/grpc_interop_node/build_interop.sh
+++ b/tools/dockerfile/grpc_interop_node/build_interop.sh
@@ -41,8 +41,6 @@ cd /var/local/git/grpc
 nvm use 0.12
 nvm alias default 0.12  # prevent the need to run 'nvm use' in every shell
 
-make install-certs
-
 # build Node interop client & server
 npm install -g node-gyp
 npm install --unsafe-perm --build-from-source
diff --git a/tools/dockerfile/grpc_interop_ruby/build_interop.sh b/tools/dockerfile/grpc_interop_ruby/build_interop.sh
index 685397bac2d4f4f71f93a6f0aeb57d721cd28008..97b3860f9813a5158aeb658e802a9a292cd6243e 100755
--- a/tools/dockerfile/grpc_interop_ruby/build_interop.sh
+++ b/tools/dockerfile/grpc_interop_ruby/build_interop.sh
@@ -40,7 +40,5 @@ cp -r /var/local/jenkins/service_account $HOME || true
 cd /var/local/git/grpc
 rvm --default use ruby-2.1
 
-make install-certs
-
 # build Ruby interop client and server
 (cd src/ruby && gem update bundler && bundle && rake compile)