diff --git a/images/core.proto b/images/core.proto
index 1fa23868b..10811fbfd 100644
--- a/images/core.proto
+++ b/images/core.proto
@@ -111,6 +111,7 @@ message thread_core_entry {
 	optional uint64			blk_sigset_extended	= 14;
 	optional rseq_entry		rseq_entry	= 15;
 	optional uint32			cg_set		= 16;
+	optional uint64			timerslack_ns	= 17;
 }
 
 message task_rlimits_entry {