diff --git a/tools/build_board_info.py b/tools/build_board_info.py
index de25015dd0..45612b9bc3 100644
--- a/tools/build_board_info.py
+++ b/tools/build_board_info.py
@@ -65,6 +65,8 @@ extension_by_board = {
     "microbit_v2": COMBINED_HEX,
     # stm32
     "meowbit_v121": UF2,
+    # esp32c3
+    "ai_thinker_esp32-c3s": BIN,
 }
 
 language_allow_list = set(