diff --git a/substrate/demo/primitives/src/block.rs b/substrate/demo/primitives/src/block.rs
index 4d61fb035842d1551dfd6a17397f7191b810bc3f..4183498fc74137dd478ff81b980884b630940c93 100644
--- a/substrate/demo/primitives/src/block.rs
+++ b/substrate/demo/primitives/src/block.rs
@@ -72,7 +72,7 @@ impl Slicable for Digest {
 /// The block "body": A bunch of transactions.
 pub type Body = Vec<UncheckedTransaction>;
 
-/// A Polkadot relay chain block.
+/// A block on the chain.
 #[derive(PartialEq, Eq, Clone)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
 pub struct Block {
@@ -98,9 +98,7 @@ impl Slicable for Block {
 	}
 }
 
-/// A relay chain block header.
-///
-/// https://github.com/w3f/polkadot-spec/blob/master/spec.md#header
+/// Header for a block.
 #[derive(PartialEq, Eq, Clone)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
 #[cfg_attr(feature = "std", serde(rename_all = "camelCase"))]
diff --git a/substrate/demo/primitives/src/lib.rs b/substrate/demo/primitives/src/lib.rs
index d47cd35caddf00ed267d200219ed6bb723a4d470..b0b9837de5512e5cbbd2e5388a55dbef58213468 100644
--- a/substrate/demo/primitives/src/lib.rs
+++ b/substrate/demo/primitives/src/lib.rs
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate Demo.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Shareable Polkadot types.
+//! Low-level types used throughout the Substrate Demo code.
 
 #![warn(missing_docs)]
 
diff --git a/substrate/demo/runtime/src/runtime/mod.rs b/substrate/demo/runtime/src/runtime/mod.rs
index e52e49c8aa13bd7c4e9697ed7244f9309760cbf6..bba91af86d7a832f27b050dc186166c71c8d7f4b 100644
--- a/substrate/demo/runtime/src/runtime/mod.rs
+++ b/substrate/demo/runtime/src/runtime/mod.rs
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate Demo.  If not, see <http://www.gnu.org/licenses/>.
 
-//! The Polkadot runtime.
+//! The Substrate Demo runtime.
 
 #[allow(unused)]
 pub mod system;