diff --git a/src/Lean/Elab/Deriving/TypeName.lean b/src/Lean/Elab/Deriving/TypeName.lean
index de36124868..17a0cc896a 100644
--- a/src/Lean/Elab/Deriving/TypeName.lean
+++ b/src/Lean/Elab/Deriving/TypeName.lean
@@ -23,6 +23,3 @@ private def deriveTypeNameInstance (declNames : Array Name) : CommandElabM Bool
 
 initialize
   registerDerivingHandler ``TypeName deriveTypeNameInstance
-
-deriving instance TypeName for String
-instance : Inhabited Dynamic := ⟨Dynamic.mk ""⟩