diff --git a/embed/extmod/trezorobj.h b/embed/extmod/trezorobj.h
index 2bd3a2fe97..76ff4d4c5d 100644
--- a/embed/extmod/trezorobj.h
+++ b/embed/extmod/trezorobj.h
@@ -69,4 +69,12 @@ static inline mp_uint_t trezor_obj_get_uint(mp_obj_t obj) {
     }
 }
 
+static inline uint8_t trezor_obj_get_uint8(mp_obj_t obj) {
+    mp_uint_t u = trezor_obj_get_uint(obj);
+    if (u > 0xFF) {
+        mp_raise_msg(&mp_type_OverflowError, "value does not fit into byte type");
+    }
+    return u;
+}
+
 #endif