diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 98dd3df..59abfe4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
         uses: dtolnay/rust-toolchain@1.70
 
       - name: Check tests
-        run: cargo test --all-features --no-run && cargo test
+        run: export ENV_VAR=69 && export NENV_VAR=-69 && cargo test --all-features --no-run && cargo test
 
   tests:
     runs-on: ubuntu-latest
diff --git a/Cargo.lock b/Cargo.lock
index af0cda9..7040118 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -201,7 +201,7 @@ checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
 
 [[package]]
 name = "typenum-consts"
-version = "0.1.1"
+version = "0.1.2"
 dependencies = [
  "dotenv",
  "peekmore",
diff --git a/Cargo.toml b/Cargo.toml
index d57a703..b2a120c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "typenum-consts"
-version = "0.1.1"
+version = "0.1.2"
 edition = "2021"
 authors = ["Jim Chng <jim.chng@outlook.com>"]
 exclude = [
diff --git a/README.md b/README.md
index dfcbb50..7a1cd8d 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ Procedural macros that take a literal integer (or the result of an evaluation of
 
 ### It saves time.
 
-Assuming you want a type-level positive integer `84938493`, `tnconst![+84938493]` outputs directly `typenum::PInt<U84938493>` (by the way, `U84938493` does not exist in `typenum::consts`). The alternative is to type `PInt<Sum<Prod<Exp<, ...>, ...>, ...>, ...>` (which argubly takes a lot more time).
+Assuming you want a type-level positive integer `84938493`, `tnconst![+84938493]` outputs directly `typenum::PInt<U84938493>` (by the way, `U84938493` does not exist in `typenum::consts`). The alternative is to type `PInt<Sum<Prod<Exp<..., ...>, ...>, ...>, ...>` (which argubly takes a lot more time).
 
 Example:
 
@@ -55,7 +55,7 @@ assert_eq!(
 
 ### For conditional compilation.
 
-Suppose in different environments you want a different type-level integer, you can either use `#[cfg(production)] type NUMBER = U69;` or you can do the following:
+Suppose in different environments you want a different type-level integer, you can either use e.g. `#[cfg(production)] type NUMBER = U69;` or you can do the following:
 
 ```rust
 use typenum::{U69, assert_type_eq};
@@ -108,15 +108,20 @@ type E = pconst![env!("ENV_VAR");];
 assert_type_eq!(E, P69);
 ```
 
+# Roadmap
+
+- [ ] Feature gate evaluation of mathematical expressions and reading from environment variables.
+- [ ] Enable testing for Rust version 1.70.
+
 # Vendored Crates
 
 ## [`rsc`](https://github.com/fivemoreminix/rsc/commit/67c4ddffbe45a30de0fd696c569de885bfd4e9b4) version 3.0.0
 
-Reasons for vendoring `src`.
+Reasons for vendoring `rsc`.
 
-1. As of 28 March 2024, there is a version 3.0.0 of the crate on the GitHub [repository](https://github.com/fivemoreminix/rsc/commit/67c4ddffbe45a30de0fd696c569de885bfd4e9b4) but without corresponding crate on `crates.io`.
+1. As of 28 March 2024, there is a version 3.0.0 of the crate on the GitHub [repository](https://github.com/fivemoreminix/rsc/commit/67c4ddffbe45a30de0fd696c569de885bfd4e9b4) but without a corresponding crate on `crates.io`.
 2. Easier to implement `Num` for `isize` with vendoring.
-3. `typenum-needs a mathematical expression evaluator.
+3. `typenum-const needs a mathematical expression evaluator.
 4. Its [license](https://github.com/fivemoreminix/rsc/tree/67c4ddffbe45a30de0fd696c569de885bfd4e9b4?tab=readme-ov-file#license) allows for 'usage without attribution'. Anyway, `src/vendors/rsc/Cargo.toml.vendored` is the original `Cargo.toml` file found in the repository.
 5. Thanks to [Luke Wilson](https://github.com/fivemoreminix).
 
diff --git a/src/lib.rs b/src/lib.rs
index 82623eb..5acc60c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -171,7 +171,7 @@ pub fn uconst(items: TokenStream) -> TokenStream {
 ///
 /// ## 3. Invoke by reading from an environment variable
 ///
-/// Note: `env!(...)` is a macro-like invocation. The first parameter is mandatory and is the key of the environment variable that `uconst` will read. The second parameter is optional and is the file path of the `.env.*` file to read the environment variable from, e.g. `env!("ENV_VAR", "./.env.prod")`, `"ENV_VAR"` is the key to read the value from and `"./.env.prod"` is the file path relative to [`CARGO_MANIFEST_DIR`].
+/// Note: `env!(...)` is a macro-like invocation. The first parameter is mandatory and is the key of the environment variable that `tnconst` will read. The second parameter is optional and is the file path of the `.env.*` file to read the environment variable from, e.g. `env!("ENV_VAR", "./.env.prod")`, `"ENV_VAR"` is the key to read the value from and `"./.env.prod"` is the file path relative to [`CARGO_MANIFEST_DIR`].
 ///
 /// ```rust
 /// use typenum::{U69, assert_type_eq};