diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index db16a90cc60..b648e14360c 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -214,7 +214,7 @@ pub enum SymbolManglingVersion {
 
 impl_stable_hash_via_hash!(SymbolManglingVersion);
 
-#[derive(Clone, Copy, PartialEq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Hash)]
 pub enum DebugInfo {
     None,
     Limited,