diff --git a/src/penumbra.rs b/src/penumbra.rs
index 265aead..56ff96c 100644
--- a/src/penumbra.rs
+++ b/src/penumbra.rs
@@ -58,12 +58,18 @@ enum RegenerationStep {
         to: Version,
     },
     InitThenRunTo {
+        /// The `genesis_height` is the block at which the chain will resume, post-upgrade.
+        /// For reference, this is the same block specified in an `upgrade-plan` proposal,
+        /// as the `upgradePlan.height` field.
         genesis_height: u64,
         version: Version,
         last_block: Option<u64>,
     },
     RunTo {
         version: Version,
+        /// The `last_block` is the block immediately preceding a planned chain upgrade.
+        /// For reference, this is the block specified in an `upgrade-plan` proposal,
+        /// minus 1. For chains with no known upgrade, this should be `None`.
         last_block: Option<u64>,
     },
 }
@@ -219,7 +225,6 @@ impl RegenerationPlan {
                         last_block: Some(2611800),
                     },
                 ),
-                // new content below here
                 (
                     2611800,
                     Migrate {
@@ -228,9 +233,9 @@ impl RegenerationPlan {
                     },
                 ),
                 (
-                    2611800,
+                    2611799,
                     InitThenRunTo {
-                        genesis_height: 2611801,
+                        genesis_height: 2611800,
                         version: V0o81,
                         last_block: None,
                     },