diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2266c111634..1116853641c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-04  Pedro Alves  <palves@redhat.com>
+
+	Fix build breakage.
+	* event-loop.c (gdb_do_one_event): Add default switch case.
+
 2015-02-03  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	Filter out inferior gcc option -fpreprocessed.
diff --git a/gdb/event-loop.c b/gdb/event-loop.c
index 7425b3acaa0..a2b41a75daf 100644
--- a/gdb/event-loop.c
+++ b/gdb/event-loop.c
@@ -287,6 +287,10 @@ gdb_do_one_event (void)
 	  /* Are there any asynchronous event handlers ready?  */
 	  res = check_async_event_handlers ();
 	  break;
+	default:
+	  internal_error (__FILE__, __LINE__,
+			  "unexpected event_source_head %d",
+			  event_source_head);
 	}
 
       event_source_head++;