diff --git a/substrate/frame/sudo/src/lib.rs b/substrate/frame/sudo/src/lib.rs
index 3a80c2e946..b7486edf31 100644
--- a/substrate/frame/sudo/src/lib.rs
+++ b/substrate/frame/sudo/src/lib.rs
@@ -88,10 +88,11 @@
 
 use sp_std::prelude::*;
 use sp_runtime::{
-	traits::{StaticLookup, Dispatchable}, DispatchError,
+	traits::{StaticLookup, Dispatchable, ModuleDispatchError}, DispatchError,
 };
+
 use frame_support::{
-	Parameter, decl_module, decl_event, decl_storage, ensure,
+	Parameter, decl_module, decl_event, decl_storage, decl_error, ensure,
 	weights::SimpleDispatchInfo,
 };
 use frame_system::{self as system, ensure_signed};
@@ -107,6 +108,8 @@ pub trait Trait: frame_system::Trait {
 decl_module! {
 	// Simple declaration of the `Module` type. Lets the macro know what it's working on.
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+		type Error = Error;
+
 		fn deposit_event() = default;
 
 		/// Authenticates the sudo key and dispatches a function call with `Root` origin.
@@ -122,8 +125,8 @@ decl_module! {
 		#[weight = SimpleDispatchInfo::FreeOperational]
 		fn sudo(origin, proposal: Box<T::Proposal>) {
 			// This is a public call, so we ensure that the origin is some signed account.
-			let sender = ensure_signed(origin)?;
-			ensure!(sender == Self::key(), "only the current sudo key can sudo");
+			let sender = ensure_signed(origin).map_err(|e| e.as_str())?;
+			ensure!(sender == Self::key(), Error::RequireSudo);
 
 			let res = match proposal.dispatch(frame_system::RawOrigin::Root.into()) {
 				Ok(_) => true,
@@ -148,8 +151,8 @@ decl_module! {
 		/// # </weight>
 		fn set_key(origin, new: <T::Lookup as StaticLookup>::Source) {
 			// This is a public call, so we ensure that the origin is some signed account.
-			let sender = ensure_signed(origin)?;
-			ensure!(sender == Self::key(), "only the current sudo key can change the sudo key");
+			let sender = ensure_signed(origin).map_err(|e| e.as_str())?;
+			ensure!(sender == Self::key(), Error::RequireSudo);
 			let new = T::Lookup::lookup(new)?;
 
 			Self::deposit_event(RawEvent::KeyChanged(Self::key()));
@@ -170,8 +173,8 @@ decl_module! {
 		#[weight = SimpleDispatchInfo::FixedOperational(0)]
 		fn sudo_as(origin, who: <T::Lookup as StaticLookup>::Source, proposal: Box<T::Proposal>) {
 			// This is a public call, so we ensure that the origin is some signed account.
-			let sender = ensure_signed(origin)?;
-			ensure!(sender == Self::key(), "only the current sudo key can sudo");
+			let sender = ensure_signed(origin).map_err(|e| e.as_str())?;
+			ensure!(sender == Self::key(), Error::RequireSudo);
 
 			let who = T::Lookup::lookup(who)?;
 
@@ -206,3 +209,11 @@ decl_storage! {
 		Key get(fn key) config(): T::AccountId;
 	}
 }
+
+decl_error! {
+	/// Error for the Sudo module
+	pub enum Error {
+		/// Sender must be the Sudo account
+		RequireSudo,
+	}
+}