diff --git a/src/Lean/Compiler/LCNF/Basic.lean b/src/Lean/Compiler/LCNF/Basic.lean
index b94286f19e..757f10fb4b 100644
--- a/src/Lean/Compiler/LCNF/Basic.lean
+++ b/src/Lean/Compiler/LCNF/Basic.lean
@@ -686,13 +686,13 @@ where
     decls.forM fun decl => visit decl.value
 
 def instantiateRangeArgs (e : Expr) (beginIdx endIdx : Nat) (args : Array Arg) : Expr :=
-  if !e.hasFVar then
+  if !e.hasLooseBVars then
     e
   else
     e.instantiateRange beginIdx endIdx (args.map (·.toExpr))
 
 def instantiateRevRangeArgs (e : Expr) (beginIdx endIdx : Nat) (args : Array Arg) : Expr :=
-  if !e.hasFVar then
+  if !e.hasLooseBVars then
     e
   else
     e.instantiateRevRange beginIdx endIdx (args.map (·.toExpr))