diff --git a/polkadot/runtime/rococo/Cargo.toml b/polkadot/runtime/rococo/Cargo.toml
index 2d07caea064ea..5358baa256f62 100644
--- a/polkadot/runtime/rococo/Cargo.toml
+++ b/polkadot/runtime/rococo/Cargo.toml
@@ -331,6 +331,7 @@ try-runtime = [
 	"sp-runtime/try-runtime",
 ]
 
+# When enabled, the runtime API will not be built.
 disable-runtime-api = []
 
 # Set timing constants (e.g. session period) to faster versions to speed up testing.
diff --git a/polkadot/runtime/rococo/src/lib.rs b/polkadot/runtime/rococo/src/lib.rs
index 4a64632126182..b3f67b463e6b9 100644
--- a/polkadot/runtime/rococo/src/lib.rs
+++ b/polkadot/runtime/rococo/src/lib.rs
@@ -205,21 +205,6 @@ parameter_types! {
 
 #[derive_impl(frame_system::config_preludes::RelayChainDefaultConfig)]
 impl frame_system::Config for Runtime {
-	type RuntimeOrigin = RuntimeOrigin;
-	type RuntimeEvent = RuntimeEvent;
-	type RuntimeCall = RuntimeCall;
-	type Hashing = BlakeTwo256;
-	type Lookup = AccountIdLookup<AccountId, ()>;
-	type RuntimeTask = RuntimeTask;
-	type PalletInfo = PalletInfo;
-	type OnNewAccount = ();
-	type OnKilledAccount = ();
-	type OnSetCode = ();
-	type SingleBlockMigrations = ();
-	type MultiBlockMigrator = ();
-	type PreInherents = ();
-	type PostInherents = ();
-	type PostTransactions = ();
 	type BaseCallFilter = EverythingBut<IsIdentityCall>;
 	type BlockWeights = BlockWeights;
 	type BlockLength = BlockLength;
diff --git a/polkadot/runtime/westend/Cargo.toml b/polkadot/runtime/westend/Cargo.toml
index 195b53b05f931..674e82a88532c 100644
--- a/polkadot/runtime/westend/Cargo.toml
+++ b/polkadot/runtime/westend/Cargo.toml
@@ -346,6 +346,7 @@ try-runtime = [
 	"sp-runtime/try-runtime",
 ]
 
+# When enabled, the runtime API will not be built.
 disable-runtime-api = []
 
 # Set timing constants (e.g. session period) to faster versions to speed up testing.
diff --git a/polkadot/runtime/westend/src/lib.rs b/polkadot/runtime/westend/src/lib.rs
index 1c221375f27db..065916c5c3ad6 100644
--- a/polkadot/runtime/westend/src/lib.rs
+++ b/polkadot/runtime/westend/src/lib.rs
@@ -196,21 +196,6 @@ parameter_types! {
 
 #[derive_impl(frame_system::config_preludes::RelayChainDefaultConfig)]
 impl frame_system::Config for Runtime {
-	type RuntimeOrigin = RuntimeOrigin;
-	type RuntimeEvent = RuntimeEvent;
-	type RuntimeCall = RuntimeCall;
-	type Hashing = BlakeTwo256;
-	type Lookup = AccountIdLookup<AccountId, ()>;
-	type RuntimeTask = RuntimeTask;
-	type PalletInfo = PalletInfo;
-	type OnNewAccount = ();
-	type OnKilledAccount = ();
-	type OnSetCode = ();
-	type SingleBlockMigrations = ();
-	type MultiBlockMigrator = ();
-	type PreInherents = ();
-	type PostInherents = ();
-	type PostTransactions = ();
 	type BaseCallFilter = EverythingBut<IsIdentityCall>;
 	type BlockWeights = BlockWeights;
 	type BlockLength = BlockLength;