diff --git a/src/libstd/ebml.rs b/src/libstd/ebml.rs
index 864a49a1429..af433c6dd9d 100644
--- a/src/libstd/ebml.rs
+++ b/src/libstd/ebml.rs
@@ -379,6 +379,7 @@ pub mod reader {
         fn read_int(&mut self) -> int {
             let v = doc_as_u64(self.next_doc(EsInt)) as i64;
             if v > (int::max_value as i64) || v < (int::min_value as i64) {
+                debug!("FIXME #6122: Removing this makes this function miscompile");
                 fail!(fmt!("int %? out of range for this architecture", v));
             }
             v as int