diff --git a/core/definitions.mk b/core/definitions.mk
index 857b73c..8d7e3ff 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1124,7 +1124,7 @@
 @mkdir -p $(dir $@)
 @mkdir -p $(PRIVATE_HEADER_OUTPUT_DIR)
 @echo "Generating C++ from AIDL: $(PRIVATE_MODULE) <= $<"
-$(hide) $(AIDL_CPP) -d$(basename $@).aidl.d -ninja $(PRIVATE_AIDL_FLAGS) \
+$(hide) $(AIDL_CPP) -d$(basename $@).aidl.d --ninja $(PRIVATE_AIDL_FLAGS) \
     $< $(PRIVATE_HEADER_OUTPUT_DIR) $@
 endef