diff --git a/src/common/log.cpp b/src/common/log.cpp
index f120d6440d..1919342e23 100644
--- a/src/common/log.cpp
+++ b/src/common/log.cpp
@@ -611,7 +611,7 @@ void wxLog::ClearTraceMasks()
 void wxLog::TimeStamp(wxString *str)
 {
 #if wxUSE_DATETIME
-    if ( ms_timestamp )
+    if ( !ms_timestamp.empty() )
     {
         wxChar buf[256];
         time_t timeNow;