diff --git a/gtk/details.c b/gtk/details.c
index 4b5b0590d..8c354781c 100644
--- a/gtk/details.c
+++ b/gtk/details.c
@@ -1144,7 +1144,7 @@ refresh_time_lb( GtkWidget * l, time_t t )
     if( !t )
         gtk_label_set_text( GTK_LABEL( l ), never );
     else {
-        char * str = rfc822date( t * 1000 );
+        char * str = rfc822date( (guint64)t * 1000 );
         gtk_label_set_text( GTK_LABEL( l ), str );
         g_free( str );
     }
diff --git a/gtk/msgwin.c b/gtk/msgwin.c
index 9b4fc0b0e..8850c9f72 100644
--- a/gtk/msgwin.c
+++ b/gtk/msgwin.c
@@ -97,7 +97,7 @@ doSave( GtkWindow      * parent,
             gtk_tree_model_get( model, &iter,
                                 COL_TR_MSG, &node,
                                 -1 );
-            date = rfc822date( node->when*1000u );
+            date = rfc822date( (guint64)node->when * 1000u );
             switch( node->level ) {
                 case TR_MSG_DBG: levelStr = "debug"; break;
                 case TR_MSG_ERR: levelStr = "error"; break;