diff --git a/sdbusplus.hpp b/sdbusplus.hpp
index 6787f49..909fbc3 100644
--- a/sdbusplus.hpp
+++ b/sdbusplus.hpp
@@ -306,7 +306,7 @@
             }
             return mapperResp.begin()->first;
         }
-        catch (DBusMethodError& e)
+        catch (const DBusMethodError& e)
         {
             throw DBusServiceError{path, interface};
         }