diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index 28367f25267..b880f312715 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -242,7 +242,7 @@
 /// rustc. Please check with the compiler team before adding an entry.
 const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     // tidy-alphabetical-start
-    "adler",
+    "adler2",
     "ahash",
     "aho-corasick",
     "allocator-api2", // FIXME: only appears in Cargo.lock due to https://github.com/rust-lang/cargo/issues/10801