diff --git a/lib/build.sh b/lib/build.sh
index 613858f08..760253452 100755
--- a/lib/build.sh
+++ b/lib/build.sh
@@ -240,7 +240,7 @@ write_profile() {
 
 write_export() {
   info "Exporting binary paths"
-  echo "export PATH=\"$build_dir/.heroku/node/bin:$build_dir/node_modules/.bin:\$build_dir/.gem/ruby/2.2.0/bin:\$PATH\"" > $bp_dir/export
+  echo "export PATH=\"$build_dir/.heroku/node/bin:$build_dir/node_modules/.bin:$build_dir/.gem/ruby/2.2.0/bin:\$PATH\"" > $bp_dir/export
   echo "export NODE_HOME=\"$build_dir/.heroku/node\"" >> $bp_dir/export
   echo "export GEM_HOME=\"$build_dir/.gem/ruby/2.2.0\"" >> $bp_dir/export
   . $bp_dir/export