diff --git a/libflux/flux/src/cffi.rs b/libflux/flux/src/cffi.rs
index f3865b83ad..37e8d3bcb7 100644
--- a/libflux/flux/src/cffi.rs
+++ b/libflux/flux/src/cffi.rs
@@ -97,7 +97,7 @@ pub extern "C" fn flux_free_error(_err: Option<Box<ErrorHandle>>) {}
 /// function is called twice on the same raw pointer.
 #[no_mangle]
 pub unsafe extern "C" fn flux_free_bytes(cstr: *mut c_char) {
-    Box::from_raw(cstr);
+    drop(Box::from_raw(cstr));
 }
 
 /// A buffer of flux source.