diff --git a/hercules_opt/src/editor.rs b/hercules_opt/src/editor.rs
index bd449ce374efa37f785660a1e075465be9ca69a2..9cf5af72e2945b35337a7e1da871d9a4c5e06fb5 100644
--- a/hercules_opt/src/editor.rs
+++ b/hercules_opt/src/editor.rs
@@ -820,6 +820,9 @@ impl<'a, 'b> FunctionEdit<'a, 'b> {
             Type::Product(_) | Type::Summation(_) | Type::Array(_, _) => {
                 panic!("PANIC: Can't create largest constant of a collection type.")
             }
+            Type::MultiReturn(_) => {
+                panic!("PANIC: Can't create largest constant for multi-return types.")
+            }
         };
         self.add_constant(constant_to_construct)
     }
@@ -843,6 +846,9 @@ impl<'a, 'b> FunctionEdit<'a, 'b> {
             Type::Product(_) | Type::Summation(_) | Type::Array(_, _) => {
                 panic!("PANIC: Can't create smallest constant of a collection type.")
             }
+            Type::MultiReturn(_) => {
+                panic!("PANIC: Can't create smallest constant for multi-return types.")
+            }
         };
         self.add_constant(constant_to_construct)
     }