diff --git a/src/Lean/Parser/Do.lean b/src/Lean/Parser/Do.lean
index e69297bb2c..c10003ca89 100644
--- a/src/Lean/Parser/Do.lean
+++ b/src/Lean/Parser/Do.lean
@@ -85,7 +85,7 @@ def doFinally    := parser! "finally " >> doSeq
 
 @[builtinDoElemParser] def doBreak     := parser! "break"
 @[builtinDoElemParser] def doContinue  := parser! "continue"
-@[builtinDoElemParser] def doReturn    := parser!:leadPrec "return " >> optional termParser
+@[builtinDoElemParser] def doReturn    := parser!:leadPrec withPosition ("return " >> optional (checkLineEq >> termParser))
 @[builtinDoElemParser] def doDbgTrace  := parser!:leadPrec "dbgTrace! " >> ((interpolatedStr termParser) <|> termParser)
 @[builtinDoElemParser] def doAssert    := parser!:leadPrec "assert! " >> termParser
 
diff --git a/tests/lean/run/returnOptIssue.lean b/tests/lean/run/returnOptIssue.lean
new file mode 100644
index 0000000000..ed9b6df1ff
--- /dev/null
+++ b/tests/lean/run/returnOptIssue.lean
@@ -0,0 +1,8 @@
+#lang lean4
+
+def f (x : Nat) : IO Unit := do
+if x > 10 then
+  return
+throw $ IO.userError "x ≤ 10"
+
+#eval f 11