diff --git a/rand-extension/README.md b/rand-extension/README.md
index 19d4cc48..5b2731a4 100644
--- a/rand-extension/README.md
+++ b/rand-extension/README.md
@@ -22,6 +22,7 @@ To integrate this example into Substrate you need to do two things:
 
 * Use the implementation as the associated type `ChainExtension` of the trait
   `pallet_contracts::Config`:
+
   ```rust
   impl pallet_contracts::Config for Runtime {
     …
@@ -32,4 +33,4 @@ To integrate this example into Substrate you need to do two things:
 
 ## ink! Integration
 
-See the example contract in [`lib.rs`](lib.rs).
+See the example contract in [`contract/lib.rs`](contract/lib.rs).
diff --git a/rand-extension/contract/Cargo.toml b/rand-extension/contract/Cargo.toml
new file mode 100644
index 00000000..51092957
--- /dev/null
+++ b/rand-extension/contract/Cargo.toml
@@ -0,0 +1,26 @@
+[package]
+name = "rand_contract"
+version = "4.2.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2021"
+publish = false
+
+[dependencies]
+ink = { version = "4.2", default-features = false }
+scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
+scale-info = { version = "2.5", default-features = false, features = ["derive"] }
+rand_extension = { version = "1.0.0", path = "../rand_extension", default-features = false  }
+
+[lib]
+path = "lib.rs"
+
+[features]
+default = ["std"]
+std = [
+    "ink/std",
+    "scale/std",
+    "scale-info/std",
+    "rand_extension/std"
+]
+ink-as-dependency = []
+
diff --git a/rand-extension/lib.rs b/rand-extension/contract/lib.rs
old mode 100755
new mode 100644
similarity index 78%
rename from rand-extension/lib.rs
rename to rand-extension/contract/lib.rs
index 3b61b057..e738df75
--- a/rand-extension/lib.rs
+++ b/rand-extension/contract/lib.rs
@@ -1,38 +1,7 @@
 #![cfg_attr(not(feature = "std"), no_std, no_main)]
 
 use ink::env::Environment;
-
-/// This is an example of how an ink! contract may call the Substrate
-/// runtime function `RandomnessCollectiveFlip::random_seed`. See the
-/// file `runtime/chain-extension-example.rs` for that implementation.
-///
-/// Here we define the operations to interact with the Substrate runtime.
-#[ink::chain_extension]
-pub trait FetchRandom {
-    type ErrorCode = RandomReadErr;
-
-    /// Note: this gives the operation a corresponding `func_id` (1101 in this case),
-    /// and the chain-side chain extension will get the `func_id` to do further
-    /// operations.
-    #[ink(extension = 1101)]
-    fn fetch_random(subject: [u8; 32]) -> [u8; 32];
-}
-
-#[derive(Debug, Copy, Clone, PartialEq, Eq, scale::Encode, scale::Decode)]
-#[cfg_attr(feature = "std", derive(scale_info::TypeInfo))]
-pub enum RandomReadErr {
-    FailGetRandomSource,
-}
-
-impl ink::env::chain_extension::FromStatusCode for RandomReadErr {
-    fn from_status_code(status_code: u32) -> Result<(), Self> {
-        match status_code {
-            0 => Ok(()),
-            1 => Err(Self::FailGetRandomSource),
-            _ => panic!("encountered unknown status code"),
-        }
-    }
-}
+use rand_extension::FetchRandom;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "std", derive(scale_info::TypeInfo))]
@@ -52,8 +21,8 @@ impl Environment for CustomEnvironment {
 }
 
 #[ink::contract(env = crate::CustomEnvironment)]
-mod rand_extension {
-    use super::RandomReadErr;
+mod rand_contract {
+    use rand_extension::RandomReadErr;
 
     /// Defines the storage of our contract.
     ///
diff --git a/rand-extension/Cargo.toml b/rand-extension/rand_extension/Cargo.toml
old mode 100755
new mode 100644
similarity index 86%
rename from rand-extension/Cargo.toml
rename to rand-extension/rand_extension/Cargo.toml
index 194390ab..c505f8b5
--- a/rand-extension/Cargo.toml
+++ b/rand-extension/rand_extension/Cargo.toml
@@ -1,18 +1,14 @@
 [package]
 name = "rand_extension"
-version = "4.2.0"
+version = "1.0.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2021"
 publish = false
 
 [dependencies]
 ink = { version = "4.2", default-features = false }
-
 scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
-scale-info = { version = "2.5", default-features = false, features = ["derive"], optional = true }
-
-[lib]
-path = "lib.rs"
+scale-info = { version = "2.5", default-features = false, features = ["derive"] }
 
 [features]
 default = ["std"]
diff --git a/rand-extension/rand_extension/src/lib.rs b/rand-extension/rand_extension/src/lib.rs
new file mode 100644
index 00000000..7dfc7adc
--- /dev/null
+++ b/rand-extension/rand_extension/src/lib.rs
@@ -0,0 +1,33 @@
+#![cfg_attr(not(feature = "std"), no_std, no_main)]
+
+/// This is an example of how an ink! contract may call the Substrate
+/// runtime function `RandomnessCollectiveFlip::random_seed`. See the
+/// file `runtime/chain-extension-example.rs` for that implementation.
+///
+/// Here we define the operations to interact with the Substrate runtime.
+#[ink::chain_extension]
+pub trait FetchRandom {
+    type ErrorCode = RandomReadErr;
+
+    /// Note: this gives the operation a corresponding `func_id` (1101 in this case),
+    /// and the chain-side chain extension will get the `func_id` to do further
+    /// operations.
+    #[ink(extension = 1101)]
+    fn fetch_random(subject: [u8; 32]) -> [u8; 32];
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, scale::Encode, scale::Decode)]
+#[cfg_attr(feature = "std", derive(scale_info::TypeInfo))]
+pub enum RandomReadErr {
+    FailGetRandomSource,
+}
+
+impl ink::env::chain_extension::FromStatusCode for RandomReadErr {
+    fn from_status_code(status_code: u32) -> Result<(), Self> {
+        match status_code {
+            0 => Ok(()),
+            1 => Err(Self::FailGetRandomSource),
+            _ => panic!("encountered unknown status code"),
+        }
+    }
+}