diff --git a/packages/api-derive/src/session/info.ts b/packages/api-derive/src/session/info.ts
index 5a5d419eda..f6bd7db72f 100644
--- a/packages/api-derive/src/session/info.ts
+++ b/packages/api-derive/src/session/info.ts
@@ -39,8 +39,6 @@ function createDerivedV1 (api: ApiInterfaceRx, [bestNumber, { currentIndex, vali
     eraLength: createType(api.registry, 'BlockNumber', sessionLength.mul(sessionsPerEra)),
     eraProgress: createType(api.registry, 'BlockNumber', eraProgress),
     isEpoch: false,
-    lastEraLengthChange,
-    lastLengthChange,
     sessionLength,
     sessionsPerEra,
     sessionProgress: createType(api.registry, 'BlockNumber', sessionProgress),
@@ -59,8 +57,6 @@ function createDerivedLatest (api: ApiInterfaceRx, [[hasBabe, epochDuration, ses
     eraLength: createType(api.registry, 'BlockNumber', sessionsPerEra.mul(epochDuration)),
     eraProgress: createType(api.registry, 'BlockNumber', eraProgress),
     isEpoch: hasBabe,
-    lastEraLengthChange: createType(api.registry, 'BlockNumber'),
-    lastLengthChange: createType(api.registry, 'BlockNumber', epochStartSlot),
     sessionLength: epochDuration,
     sessionsPerEra,
     sessionProgress: createType(api.registry, 'BlockNumber', sessionProgress),
diff --git a/packages/api-derive/src/types.ts b/packages/api-derive/src/types.ts
index ba298f21af..47f8e2bbe9 100644
--- a/packages/api-derive/src/types.ts
+++ b/packages/api-derive/src/types.ts
@@ -97,8 +97,6 @@ export interface DerivedSessionInfo extends DeriveSessionIndexes {
   eraLength: BlockNumber;
   eraProgress: BlockNumber;
   isEpoch: boolean;
-  lastEraLengthChange: BlockNumber;
-  lastLengthChange: BlockNumber;
   sessionLength: BlockNumber;
   sessionsPerEra: SessionIndex;
   sessionProgress: BlockNumber;