diff --git a/runtime/kusama/src/lib.rs b/runtime/kusama/src/lib.rs
index c841c552f919..89507400a747 100644
--- a/runtime/kusama/src/lib.rs
+++ b/runtime/kusama/src/lib.rs
@@ -90,7 +90,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("kusama"),
 	impl_name: create_runtime_str!("parity-kusama"),
 	authoring_version: 2,
-	spec_version: 2022,
+	spec_version: 2023,
 	impl_version: 0,
 	#[cfg(not(feature = "disable-runtime-api"))]
 	apis: RUNTIME_API_VERSIONS,
@@ -317,8 +317,8 @@ parameter_types! {
 	pub const SessionsPerEra: SessionIndex = 6;
 	// 28 eras for unbonding (7 days).
 	pub const BondingDuration: staking::EraIndex = 28;
-	// 28 eras in which slashes can be cancelled (7 days).
-	pub const SlashDeferDuration: staking::EraIndex = 28;
+	// 27 eras in which slashes can be cancelled (slightly less than 7 days).
+	pub const SlashDeferDuration: staking::EraIndex = 27;
 	pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
 	pub const MaxNominatorRewardedPerValidator: u32 = 64;
 	// quarter of the last session will be for election.
@@ -1337,3 +1337,16 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::Runtime;
+
+	#[test]
+	fn slash_defer_less_than_bonding_duration() {
+		assert!(
+			<Runtime as staking::Trait>::SlashDeferDuration::get()
+				< <Runtime as staking::Trait>::BondingDuration::get()
+		);
+	}
+}
diff --git a/runtime/polkadot/src/lib.rs b/runtime/polkadot/src/lib.rs
index b683a66c754e..1a922dc72ef2 100644
--- a/runtime/polkadot/src/lib.rs
+++ b/runtime/polkadot/src/lib.rs
@@ -89,7 +89,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("polkadot"),
 	impl_name: create_runtime_str!("parity-polkadot"),
 	authoring_version: 0,
-	spec_version: 22,
+	spec_version: 23,
 	impl_version: 0,
 	#[cfg(not(feature = "disable-runtime-api"))]
 	apis: RUNTIME_API_VERSIONS,
@@ -329,7 +329,7 @@ parameter_types! {
 	pub const SessionsPerEra: SessionIndex = 6;
 	// 28 eras for unbonding (28 days).
 	pub const BondingDuration: staking::EraIndex = 28;
-	pub const SlashDeferDuration: staking::EraIndex = 28;
+	pub const SlashDeferDuration: staking::EraIndex = 27;
 	pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
 	pub const MaxNominatorRewardedPerValidator: u32 = 64;
 	// last 15 minutes of the last session will be for election.
@@ -1475,3 +1475,16 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::Runtime;
+
+	#[test]
+	fn slash_defer_less_than_bonding_duration() {
+		assert!(
+			<Runtime as staking::Trait>::SlashDeferDuration::get()
+				< <Runtime as staking::Trait>::BondingDuration::get()
+		);
+	}
+}
diff --git a/runtime/westend/src/lib.rs b/runtime/westend/src/lib.rs
index e9aa1a154110..93742b02c58b 100644
--- a/runtime/westend/src/lib.rs
+++ b/runtime/westend/src/lib.rs
@@ -86,7 +86,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("westend"),
 	impl_name: create_runtime_str!("parity-westend"),
 	authoring_version: 2,
-	spec_version: 42,
+	spec_version: 43,
 	impl_version: 0,
 	#[cfg(not(feature = "disable-runtime-api"))]
 	apis: RUNTIME_API_VERSIONS,
@@ -294,8 +294,8 @@ parameter_types! {
 	pub const SessionsPerEra: SessionIndex = 6;
 	// 28 eras for unbonding (7 days).
 	pub const BondingDuration: staking::EraIndex = 28;
-	// 28 eras in which slashes can be cancelled (7 days).
-	pub const SlashDeferDuration: staking::EraIndex = 28;
+	// 27 eras in which slashes can be cancelled (slightly less than 7 days).
+	pub const SlashDeferDuration: staking::EraIndex = 27;
 	pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
 	pub const MaxNominatorRewardedPerValidator: u32 = 64;
 	// quarter of the last session will be for election.
@@ -1113,3 +1113,16 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::Runtime;
+
+	#[test]
+	fn slash_defer_less_than_bonding_duration() {
+		assert!(
+			<Runtime as staking::Trait>::SlashDeferDuration::get()
+				< <Runtime as staking::Trait>::BondingDuration::get()
+		);
+	}
+}