diff --git a/include/wx/log.h b/include/wx/log.h
index 4bc3b587b8..514dc84b6b 100644
--- a/include/wx/log.h
+++ b/include/wx/log.h
@@ -395,18 +395,13 @@ public:
 
     // return the effective log level for this component, falling back to
     // parent component and to the default global log level if necessary
-    //
-    // NB: component argument is passed by value and not const reference in an
-    //     attempt to encourage compiler to avoid an extra copy: as we modify
-    //     the component internally, we'd create one anyhow and like this it
-    //     can be avoided if the string is a temporary anyhow
-    static wxLogLevel GetComponentLevel(wxString component);
+    static wxLogLevel GetComponentLevel(const wxString& component);
 
 
     // is logging of messages from this component enabled at this level?
     //
     // usually always called with wxLOG_COMPONENT as second argument
-    static bool IsLevelEnabled(wxLogLevel level, wxString component)
+    static bool IsLevelEnabled(wxLogLevel level, const wxString& component)
     {
         return IsEnabled() && level <= GetComponentLevel(component);
     }
diff --git a/src/common/log.cpp b/src/common/log.cpp
index fe169a6b45..04b910d724 100644
--- a/src/common/log.cpp
+++ b/src/common/log.cpp
@@ -603,10 +603,13 @@ void wxLog::SetComponentLevel(const wxString& component, wxLogLevel level)
 }
 
 /* static */
-wxLogLevel wxLog::GetComponentLevel(wxString component)
+wxLogLevel wxLog::GetComponentLevel(const wxString& componentOrig)
 {
     wxCRIT_SECT_LOCKER(lock, GetLevelsCS());
 
+    // Make a copy before modifying it in the loop.
+    wxString component = componentOrig;
+
     const wxStringToNumHashMap& componentLevels = GetComponentLevels();
     while ( !component.empty() )
     {