diff --git a/gtk2_ardour/utils.cc b/gtk2_ardour/utils.cc
index 8650e0da78..aa68519560 100644
--- a/gtk2_ardour/utils.cc
+++ b/gtk2_ardour/utils.cc
@@ -611,6 +611,7 @@ key_is_legal_for_numeric_entry (guint keyval)
 
 	switch (keyval) {
 	case GDK_decimalpoint:
+	case GDK_KP_Separator:
 		return true;
 
 	case GDK_period: