diff --git a/services/lib/docker/proto_codegen.sh b/services/lib/docker/proto_codegen.sh
index 00f8470bd..821384f82 100755
--- a/services/lib/docker/proto_codegen.sh
+++ b/services/lib/docker/proto_codegen.sh
@@ -1,11 +1,11 @@
 #!/usr/bin/env bash
 
 set -e
 
 echo "generating files from protos..."
 
-for PROTO_FILE in $(ls ./protos); do
-  protoc -I=./protos --cpp_out=_generated --grpc_out=_generated --plugin=protoc-gen-grpc=`which grpc_cpp_plugin` ./protos/$PROTO_FILE
+for PROTO_FILE in ./protos/*; do
+  protoc -I=./protos --cpp_out=_generated --grpc_out=_generated --plugin=protoc-gen-grpc="$(which grpc_cpp_plugin)" ./"$PROTO_FILE"
 done
 
 echo "success - code generated from protos"