diff --git a/src/Lean/Elab/StructInst.lean b/src/Lean/Elab/StructInst.lean
index fa22c7ece8..1095a6a49d 100644
--- a/src/Lean/Elab/StructInst.lean
+++ b/src/Lean/Elab/StructInst.lean
@@ -25,8 +25,8 @@ open Meta
 
 @[builtinMacro Lean.Parser.Term.structInst] def expandStructInstExpectedType : Macro := fun stx =>
   let expectedArg := stx[4]
-  if expectedArg.isNone
-    then Macro.throwUnsupported
+  if expectedArg.isNone then
+    Macro.throwUnsupported
   else
     let expected := expectedArg[1]
     let stxNew   := stx.setArg 4 mkNullNode