diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 0901be1..53ee00b 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         platform: [ ubuntu-latest, macos-latest, windows-latest ]
-        toolchain: [ stable, 1.35.0, nightly ]
+        toolchain: [ stable, 1.51.0, nightly ]
       fail-fast: false
     runs-on: ${{ matrix.platform }}
     steps:
diff --git a/README.md b/README.md
index 8455d35..68e3a84 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# nod-rs [![Build Status]][actions] [![Latest Version]][crates.io] [![Api Rustdoc]][rustdoc] [![Rust](https://img.shields.io/badge/rust-1.35%2B-blue.svg?maxAge=3600)](https://github.com/eqrion/cbindgen)
+# nod-rs [![Build Status]][actions] [![Latest Version]][crates.io] [![Api Rustdoc]][rustdoc] [![Rust](https://img.shields.io/badge/rust-1.51%2B-blue.svg?maxAge=3600)](https://github.com/eqrion/cbindgen)
 
 [Build Status]: https://github.com/encounter/nod-rs/workflows/build/badge.svg
 [actions]: https://github.com/encounter/nod-rs/actions
diff --git a/src/io/mod.rs b/src/io/mod.rs
index c630b31..7ea8b2c 100644
--- a/src/io/mod.rs
+++ b/src/io/mod.rs
@@ -24,7 +24,9 @@ pub trait DiscIO {
 #[inline(always)]
 pub fn has_extension(filename: &Path, extension: &str) -> bool {
     if let Some(ext) = filename.extension() {
-        ext.eq_ignore_ascii_case(extension)
+        // TODO use with Rust 1.53+
+        // ext.eq_ignore_ascii_case(extension)
+        ext.to_str().unwrap_or("").eq_ignore_ascii_case(extension)
     } else { false }
 }