diff --git a/src/branches.cpp b/src/branches.cpp
index 26f1c29c..a0ffe287 100644
--- a/src/branches.cpp
+++ b/src/branches.cpp
@@ -452,7 +452,7 @@ Branches::to_string(void) const
 void
 Branches::find_and_set_mode_ro()
 {
-  auto impl = std::atomic_load(&_impl);
+  Branches::Ptr impl = std::atomic_load(&_impl);
   auto new_impl = std::make_shared<Branches::Impl>(impl->minfreespace());
 
   *new_impl = *impl;