diff --git a/include/xrpl/protocol/detail/features.macro b/include/xrpl/protocol/detail/features.macro
index 4f1fac82da..ec5d8bfa03 100644
--- a/include/xrpl/protocol/detail/features.macro
+++ b/include/xrpl/protocol/detail/features.macro
@@ -15,6 +15,7 @@
 // Add new amendments to the top of this list.
 // Keep it sorted in reverse chronological order.
 
+XRPL_FEATURE(Cosign,                      Supported::No,  VoteBehavior::DefaultNo)
 XRPL_FIX    (Cleanup3_4_0,                Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(Sponsor,                     Supported::Yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(BatchV1_1,                   Supported::Yes, VoteBehavior::DefaultNo)