diff --git a/prism_compile.c b/prism_compile.c
index 51fd657217..2598f38e0c 100644
--- a/prism_compile.c
+++ b/prism_compile.c
@@ -2589,7 +2589,7 @@ pm_scope_node_init(const pm_node_t *node, pm_scope_node_t *scope, pm_scope_node_
         break;
       }
       default:
-        assert(false && "unreachable");
+        rb_bug("unreachable");
         break;
     }
 }