diff --git a/extmod/btstack/btstack.mk b/extmod/btstack/btstack.mk
index 7e5d2f646d..e3309b61db 100644
--- a/extmod/btstack/btstack.mk
+++ b/extmod/btstack/btstack.mk
@@ -66,11 +66,12 @@ endif
 LIB_SRC_C += $(SRC_BTSTACK)
 
 # Suppress some warnings.
-BTSTACK_WARNING_CFLAGS = -Wno-old-style-definition -Wno-unused-variable -Wno-unused-parameter
+BTSTACK_WARNING_CFLAGS = -Wno-old-style-definition -Wno-unused-variable -Wno-unused-parameter -Wimplicit-fallthrough=0
 ifneq ($(CC),clang)
 BTSTACK_WARNING_CFLAGS += -Wno-format
 endif
 $(BUILD)/lib/btstack/src/%.o: CFLAGS += $(BTSTACK_WARNING_CFLAGS)
+$(BUILD)/lib/btstack/platform/%.o: CFLAGS += $(BTSTACK_WARNING_CFLAGS)
 
 endif
 endif