diff --git a/libgrust/libformat_parser/src/lib.rs b/libgrust/libformat_parser/src/lib.rs
index 84fac38e224..28f6a6a62b6 100644
--- a/libgrust/libformat_parser/src/lib.rs
+++ b/libgrust/libformat_parser/src/lib.rs
@@ -5,6 +5,13 @@
 
 use std::ffi::CStr;
 
+// Local replacement for 1.72.0+ method 'leak' for struct 'std::string::String',
+// <https://doc.rust-lang.org/1.72.0/src/alloc/string.rs.html#1853>
+fn leak_string<'a>(s: String) -> &'a mut str {
+    let slice = s.into_bytes().leak();
+    unsafe { std::str::from_utf8_unchecked_mut(slice) }
+}
+
 trait IntoFFI<T> {
     fn into_ffi(self) -> T;
 }
@@ -393,7 +400,7 @@ pub extern "C" fn collect_pieces(
     let rust_string = RustString {
         len: str.len(),
         cap: str.capacity(),
-        ptr: str.leak().as_ptr(),
+        ptr: leak_string(str).as_ptr(),
     };
 
     FormatArgsHandle(piece_slice, rust_string)
@@ -431,12 +438,12 @@ pub extern "C" fn clone_pieces(
     let cloned_s = s.clone();
 
     // FIXME: Documentation
-    s.leak();
+    leak_string(s);
 
     let rust_string = RustString {
         len: cloned_s.len(),
         cap: cloned_s.capacity(),
-        ptr: cloned_s.leak().as_ptr(),
+        ptr: leak_string(cloned_s).as_ptr(),
     };
 
     FormatArgsHandle(piece_slice, rust_string)