diff --git a/Cargo.lock b/Cargo.lock
index 7d981de6..49ffa66d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
 version = "0.6.8"
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index df997d5e..76dd16b9 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -61,7 +61,7 @@ pub fn id_from_content(content: &str) -> String {
     }
 
     // Remove spaces and hashes indicating a header
-    let trimmed = content.trim().trim_left_matches('#').trim();
+    let trimmed = content.trim().trim_start_matches('#').trim();
 
     normalize_id(trimmed)
 }
diff --git a/tests/rendered_output.rs b/tests/rendered_output.rs
index b7777ee7..062674a3 100644
--- a/tests/rendered_output.rs
+++ b/tests/rendered_output.rs
@@ -423,8 +423,8 @@ mod search {
     fn read_book_index(root: &Path) -> serde_json::Value {
         let index = root.join("book/searchindex.js");
         let index = file_to_string(index).unwrap();
-        let index = index.trim_left_matches("window.search = ");
-        let index = index.trim_right_matches(";");
+        let index = index.trim_start_matches("window.search = ");
+        let index = index.trim_end_matches(";");
         serde_json::from_str(&index).unwrap()
     }