diff --git a/proto/update.sh b/proto/update.sh
index 97c44e04a..d7185e566 100755
--- a/proto/update.sh
+++ b/proto/update.sh
@@ -2,7 +2,7 @@
 
 # Update bundled .proto files
 
-cd $(pwd)
+cd "$(pwd)"
 
 rm -rf google
 mkdir -p google/protobuf/compiler