diff --git a/src/common/datetime.cpp b/src/common/datetime.cpp
index 787e9c2fac..a2e2bc13f0 100644
--- a/src/common/datetime.cpp
+++ b/src/common/datetime.cpp
@@ -2870,7 +2870,7 @@ const wxChar *wxDateTime::ParseFormat(const wxChar *date,
         // take this date as default
         tmDef = dateDef.GetTm();
     }
-    else if ( m_time != 0 )
+    else if ( m_time != wxLongLong(0) )
     {
         // if this date is valid, don't change it
         tmDef = GetTm();