diff --git a/callout.cpp b/callout.cpp
index 6c96455..3f409f9 100644
--- a/callout.cpp
+++ b/callout.cpp
@@ -161,7 +161,7 @@
 
         iarchive(*this);
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         log<level::ERR>(e.what());
         log<level::ERR>("Failed trying to restore a Callout object",