diff --git a/gramps/src/plugins/WriteGedcom.py b/gramps/src/plugins/WriteGedcom.py
index 629fc3ffa..ecc275c72 100644
--- a/gramps/src/plugins/WriteGedcom.py
+++ b/gramps/src/plugins/WriteGedcom.py
@@ -345,7 +345,7 @@ def write_source_ref(g,level,ref):
         if ref_text != "":
             write_long_text(g,"TEXT",level+1,ref_text)
         if ref.getDate().getDate():
-            g.write("%d DATE %s\n",level+1,ref.getDate().getSaveDate())
+            g.write("%d DATE %s\n" % (level+1,ref.getDate().getSaveDate()))
     if ref.getComments() != "":
         write_long_text(g,"NOTE",level+1,ref.getComments())