diff --git a/Cargo.lock b/Cargo.lock
index 9464c87fc728b..be5ceeb5f1341 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1280,7 +1280,6 @@ name = "error_index_generator"
 version = "0.0.0"
 dependencies = [
  "rustdoc",
- "walkdir",
 ]
 
 [[package]]
diff --git a/src/tools/error_index_generator/Cargo.toml b/src/tools/error_index_generator/Cargo.toml
index c84b79e11e9b4..b9fd852f742cf 100644
--- a/src/tools/error_index_generator/Cargo.toml
+++ b/src/tools/error_index_generator/Cargo.toml
@@ -6,9 +6,6 @@ edition = "2021"
 [dependencies]
 rustdoc = { path = "../../librustdoc" }
 
-[build-dependencies]
-walkdir = "2"
-
 [[bin]]
 name = "error_index_generator"
 path = "main.rs"