diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1b841d3..7c8a272 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -43,7 +43,7 @@ jobs:
       matrix:
         toolchain:
           # Oldest supported nightly
-          - nightly-2023-05-31
+          - nightly-2023-06-01
           - nightly
 
     continue-on-error: ${{ matrix.toolchain == 'nightly' }}
diff --git a/src/lib.rs b/src/lib.rs
index fb94e07..0af6431 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -136,7 +136,7 @@ pub fn check_rust_version() {
     }
 
     let old_version = MINIMUM_RUSTC_VERSION
-        >= Version {
+        > Version {
             // Remove `-nightly` pre-release tag for comparison.
             pre: semver::Prerelease::EMPTY,
             ..rustc_version.semver.clone()
@@ -146,7 +146,7 @@ pub fn check_rust_version() {
         None => false,
         Some(date) => {
             MINIMUM_COMMIT_DATE
-                >= CommitDate::parse(&date).expect("could not parse `rustc --version` commit date")
+                > CommitDate::parse(&date).expect("could not parse `rustc --version` commit date")
         }
     };