diff --git a/src/libstd/ebml.rs b/src/libstd/ebml.rs
index 934c3ae9b6b6..0c60503ce1cb 100644
--- a/src/libstd/ebml.rs
+++ b/src/libstd/ebml.rs
@@ -304,7 +304,7 @@ impl writer {
 
 // Set to true to generate more debugging in EBML serialization.
 // Totally lame approach.
-const debug: bool = true;
+const debug: bool = false;
 
 enum ebml_serializer_tag {
     es_uint, es_u64, es_u32, es_u16, es_u8,