diff --git a/qapi/common.json b/qapi/common.json
index 50ac121d25..021174f04e 100644
--- a/qapi/common.json
+++ b/qapi/common.json
@@ -140,6 +140,8 @@
 #        prefix to produce the corresponding QEMU executable name. This
 #        is true even for "qemu-system-x86_64".
 #
+# ppcemb: dropped in 3.1
+#
 # Since: 3.0
 ##
 { 'enum' : 'SysEmuTarget',