diff --git a/esp8266/mpconfigport.h b/esp8266/mpconfigport.h
index 19cf9a6792..5f65e920f1 100644
--- a/esp8266/mpconfigport.h
+++ b/esp8266/mpconfigport.h
@@ -33,6 +33,7 @@
 #define MICROPY_PY_BUILTINS_FROZENSET (1)
 #define MICROPY_PY_BUILTINS_SET     (1)
 #define MICROPY_PY_BUILTINS_SLICE   (1)
+#define MICROPY_PY_BUILTINS_SLICE_ATTRS (1)
 #define MICROPY_PY_BUILTINS_PROPERTY (1)
 #define MICROPY_PY___FILE__         (0)
 #define MICROPY_PY_GC               (1)