diff --git a/src/ck_epoch.c b/src/ck_epoch.c
index 84bbec4..9d1bb49 100644
--- a/src/ck_epoch.c
+++ b/src/ck_epoch.c
@@ -203,7 +203,7 @@ _ck_epoch_addref(struct ck_epoch_record *record,
 		previous = &record->local.bucket[(i + 1) & CK_EPOCH_SENSE];
 		if (previous->count > 0)
 			ck_pr_fence_acq_rel();
-#endif /* CK_MD_TSO */
+#endif /* !CK_MD_TSO */
 
 		/*
 		 * If this is this is a new reference into the current