diff --git a/rust/utils/src/tmpfile.rs b/rust/utils/src/tmpfile.rs
index 07acdba8..883d5586 100644
--- a/rust/utils/src/tmpfile.rs
+++ b/rust/utils/src/tmpfile.rs
@@ -16,13 +16,14 @@ fn mkdtemp<P: AsRef<Path>>(template: P) -> Result<PathBuf, std::io::Error> {
         // SAFETY: template_raw is a valid CString because it was generated by
         // the `CString::new`.
         let ret = libc::mkdtemp(template_raw);
+        // SAFETY: `template_raw` is still a valid CString because it was
+        // generated by `CString::new` and modified by `libc::mkdtemp`.
+        let path_cstr = std::ffi::CString::from_raw(template_raw);
 
         if ret.is_null() {
+            drop(path_cstr);
             Err(std::io::Error::last_os_error())
         } else {
-            // SAFETY: `template_raw` is still a valid CString because it was
-            // generated by `CString::new` and modified by `libc::mkdtemp`.
-            let path_cstr = std::ffi::CString::from_raw(template_raw);
             let path = OsStr::from_bytes(path_cstr.as_bytes());
             let path = std::path::PathBuf::from(path);