diff --git a/Cargo.lock b/Cargo.lock
index ed9375e8200a3..185d2bdf2444f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -387,7 +387,9 @@ dependencies = [
  "frame-system",
  "parity-scale-codec",
  "sp-authorship",
+ "sp-core",
  "sp-inherents",
+ "sp-io",
  "sp-runtime",
  "sp-std",
 ]
diff --git a/pallets/author-inherent/Cargo.toml b/pallets/author-inherent/Cargo.toml
index 0faf91195b514..758e73a74892a 100644
--- a/pallets/author-inherent/Cargo.toml
+++ b/pallets/author-inherent/Cargo.toml
@@ -15,6 +15,10 @@ sp-inherents = { git = "https://github.com/paritytech/substrate", branch = "mast
 sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
+[dev-dependencies]
+sp-io = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-core = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+
 [features]
 default = ["std"]
 std = [
diff --git a/pallets/author-inherent/src/lib.rs b/pallets/author-inherent/src/lib.rs
index 98eb64170929f..5e91aa6a4c61b 100644
--- a/pallets/author-inherent/src/lib.rs
+++ b/pallets/author-inherent/src/lib.rs
@@ -21,7 +21,8 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use frame_support::{
-	decl_error, decl_event, decl_module, decl_storage, ensure, weights::DispatchClass,
+	decl_error, decl_event, decl_module, decl_storage, ensure,
+	weights::{DispatchClass, Weight},
 };
 use frame_system::{ensure_none, Config as System};
 use parity_scale_codec::{Decode, Encode};
@@ -88,6 +89,11 @@ decl_module! {
 		type Error = Error<T>;
 		fn deposit_event() = default;
 
+		fn on_initialize() -> Weight {
+			<Author<T>>::kill();
+			0
+		}
+
 		/// Inherent to set the author of a block
 		#[weight = (
 			0,
@@ -116,11 +122,6 @@ decl_module! {
 
 			Self::deposit_event(Event::<T>::AuthorSet(author, current_block));
 		}
-
-		fn on_finalize() {
-			// Do we still need this now that it is required?
-			assert!(<Author<T>>::take().is_some(), "Author inherent must be in the block");
-		}
 	}
 }
 
@@ -222,3 +223,112 @@ impl<T: Config> ProvideInherent for Module<T> {
 		Ok(())
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	use frame_support::{
+		assert_noop, assert_ok, impl_outer_event, impl_outer_origin, parameter_types,
+		traits::{OnFinalize, OnInitialize},
+	};
+	use sp_core::H256;
+	use sp_io::TestExternalities;
+	use sp_runtime::{
+		testing::Header,
+		traits::{BlakeTwo256, IdentityLookup},
+	};
+
+	pub fn new_test_ext() -> TestExternalities {
+		let t = frame_system::GenesisConfig::default()
+			.build_storage::<Test>()
+			.unwrap();
+		TestExternalities::new(t)
+	}
+
+	impl_outer_origin! {
+		pub enum Origin for Test where system = frame_system {}
+	}
+
+	mod author_inherent {
+		pub use super::super::*;
+	}
+
+	impl_outer_event! {
+		pub enum MetaEvent for Test {
+			frame_system<T>,
+			author_inherent<T>,
+		}
+	}
+
+	impl<T> EventHandler<T> for () {
+		fn note_author(_author: T) {}
+	}
+
+	#[derive(Clone, Eq, PartialEq)]
+	pub struct Test;
+	parameter_types! {
+		pub const BlockHashCount: u64 = 250;
+	}
+	impl System for Test {
+		type BaseCallFilter = ();
+		type BlockWeights = ();
+		type BlockLength = ();
+		type DbWeight = ();
+		type Origin = Origin;
+		type Index = u64;
+		type BlockNumber = u64;
+		type Call = ();
+		type Hash = H256;
+		type Hashing = BlakeTwo256;
+		type AccountId = u64;
+		type Lookup = IdentityLookup<Self::AccountId>;
+		type Header = Header;
+		type Event = MetaEvent;
+		type BlockHashCount = BlockHashCount;
+		type Version = ();
+		type PalletInfo = ();
+		type AccountData = ();
+		type OnNewAccount = ();
+		type OnKilledAccount = ();
+		type SystemWeightInfo = ();
+		type SS58Prefix = ();
+	}
+	impl Config for Test {
+		type Event = MetaEvent;
+		type EventHandler = ();
+		type CanAuthor = ();
+	}
+	type AuthorInherent = Module<Test>;
+	type Sys = frame_system::Module<Test>;
+
+	pub fn roll_to(n: u64) {
+		while Sys::block_number() < n {
+			Sys::on_finalize(Sys::block_number());
+			Sys::set_block_number(Sys::block_number() + 1);
+			Sys::on_initialize(Sys::block_number());
+			AuthorInherent::on_initialize(Sys::block_number());
+		}
+	}
+
+	#[test]
+	fn set_author_works() {
+		new_test_ext().execute_with(|| {
+			assert_ok!(AuthorInherent::set_author(Origin::none(), 1));
+			roll_to(1);
+			assert_ok!(AuthorInherent::set_author(Origin::none(), 1));
+			roll_to(2);
+		});
+	}
+
+	#[test]
+	fn double_author_fails() {
+		new_test_ext().execute_with(|| {
+			assert_ok!(AuthorInherent::set_author(Origin::none(), 1));
+			assert_noop!(
+				AuthorInherent::set_author(Origin::none(), 1),
+				Error::<Test>::AuthorAlreadySet
+			);
+		});
+	}
+}
diff --git a/runtime/src/parachain.rs b/runtime/src/parachain.rs
index 9eef9deed822f..eaefe63e86581 100644
--- a/runtime/src/parachain.rs
+++ b/runtime/src/parachain.rs
@@ -22,7 +22,7 @@ macro_rules! runtime_parachain {
 			spec_name: create_runtime_str!("moonbase-alphanet"),
 			impl_name: create_runtime_str!("moonbase-alphanet"),
 			authoring_version: 3,
-			spec_version: 12,
+			spec_version: 13,
 			impl_version: 1,
 			apis: RUNTIME_API_VERSIONS,
 			transaction_version: 2,
diff --git a/runtime/src/standalone.rs b/runtime/src/standalone.rs
index 9561badc7d308..05158cdfa35b8 100644
--- a/runtime/src/standalone.rs
+++ b/runtime/src/standalone.rs
@@ -31,7 +31,7 @@ macro_rules! runtime_standalone {
 			spec_name: create_runtime_str!("moonbeam-standalone"),
 			impl_name: create_runtime_str!("moonbeam-standalone"),
 			authoring_version: 3,
-			spec_version: 12,
+			spec_version: 13,
 			impl_version: 1,
 			apis: RUNTIME_API_VERSIONS,
 			transaction_version: 2,