diff --git a/drv/cosmo-seq-server/src/main.rs b/drv/cosmo-seq-server/src/main.rs
index 609e63ced1..50374f2f15 100644
--- a/drv/cosmo-seq-server/src/main.rs
+++ b/drv/cosmo-seq-server/src/main.rs
@@ -599,6 +599,16 @@ impl ServerImpl {
 
             // This is purely an accounting change
             (PowerState::A0, PowerState::A0PlusHP) => (),
+            // A0PlusHP is a substate of A0; if we are in A0PlusHP and we are
+            // asked to go to A0, return `Unchanged`, because `A0PlusHP` means
+            // we are already in A0.
+            // Similarly, A2PlusFans "counts as" A2 for the purpose of
+            // externally-requested transitions.
+            (PowerState::A0PlusHP, PowerState::A0)
+            | (PowerState::A2PlusFans, PowerState::A2) => {
+                return Ok(Transition::Unchanged)
+            }
+            // If we are already in the requested state, return `Unchanged`.
             (current, requested) if current == requested => {
                 return Ok(Transition::Unchanged)
             }
diff --git a/drv/gimlet-seq-server/src/main.rs b/drv/gimlet-seq-server/src/main.rs
index cd92457fcc..dacc388960 100644
--- a/drv/gimlet-seq-server/src/main.rs
+++ b/drv/gimlet-seq-server/src/main.rs
@@ -967,6 +967,20 @@ impl<S: SpiServer> ServerImpl<S> {
 
                 Ok(Transition::Changed)
             }
+            //
+            // A0PlusHP is a substate of A0; if we are in A0PlusHP and we are
+            // asked to go to A0, return `Unchanged`, because `A0PlusHP` means
+            // we are already in A0.
+            // Similarly, A2PlusFans "counts as" A2 for the purpose of
+            // externally-requested transitions.
+            //
+            (PowerState::A0PlusHP, PowerState::A0)
+            | (PowerState::A2PlusFans, PowerState::A2) => {
+                Ok(Transition::Unchanged)
+            }
+            //
+            // If we are already in the requested state, return `Unchanged`.
+            //
             (current, requested) if current == requested => {
                 Ok(Transition::Unchanged)
             }