diff --git a/src/vm.rs b/src/vm.rs
index 2e95f80..5a997f6 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -590,7 +590,9 @@ impl Uxn {
                         let a = pop(wst.clone())?;
                         push(wst.clone(), (a >> right) << left)?;
                     }
-                    _ => unreachable!(),
+                    _ => {
+                        panic!("Unsupported opcode {}", Icode::nameof(icode))
+                    }
                 }
 
                 Ok(())