diff --git a/ergotree-ir/src/pretty_printer.rs b/ergotree-ir/src/pretty_printer.rs
index f5d31a1fd..5264a5849 100644
--- a/ergotree-ir/src/pretty_printer.rs
+++ b/ergotree-ir/src/pretty_printer.rs
@@ -166,7 +166,7 @@ impl Print for Expr {
             Expr::BinOp(v) => v.expr().print(w),
             Expr::GlobalVars(v) => v.print(w),
             Expr::ByIndex(v) => v.expr().print(w),
-            Expr::ConstPlaceholder(_) => todo!(),
+            Expr::ConstPlaceholder(_) => Ok(self.clone()),
             Expr::SubstConstants(_) => todo!(),
             Expr::ByteArrayToLong(_) => todo!(),
             Expr::ByteArrayToBigInt(_) => todo!(),