diff --git a/py/objtype.c b/py/objtype.c
index 83a9836c31..8ce593dba7 100644
--- a/py/objtype.c
+++ b/py/objtype.c
@@ -453,7 +453,7 @@ const qstr mp_binary_op_method_name[] = {
     /*
     MP_BINARY_OP_IS,
     */
-    [MP_BINARY_OP_EXCEPTION_MATCH] = MP_QSTR_, // not implemented, used to make sure array has full size
+    [MP_BINARY_OP_LAST] = 0, // used to make sure array has full size, TODO: FIXME
 };
 
 STATIC mp_obj_t instance_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
diff --git a/py/runtime0.h b/py/runtime0.h
index fd497a6d19..723ab582d0 100644
--- a/py/runtime0.h
+++ b/py/runtime0.h
@@ -103,6 +103,8 @@ typedef enum {
     // just identify special methods.
 
     MP_BINARY_OP_DIVMOD, // not emitted by the compiler but supported by the runtime
+
+    MP_BINARY_OP_LAST,
 } mp_binary_op_t;
 
 typedef enum {