diff --git a/backend/go/vllm-cpp/Makefile b/backend/go/vllm-cpp/Makefile
index db32e322c..1eaaae9a6 100644
--- a/backend/go/vllm-cpp/Makefile
+++ b/backend/go/vllm-cpp/Makefile
@@ -57,9 +57,10 @@ UNAME_S := $(shell uname -s)
 ifeq ($(UNAME_S),Darwin)
 	LIB=libvllm.dylib
 	# Apple Clang diagnoses a pair of constant-folded array bounds in the Metal
-	# build as a GNU extension. Disable that diagnostic because vllm.cpp appends
-	# target-local -Werror after these global flags, overriding -Wno-error.
+	# build as a GNU extension. Disable that diagnostic for both Objective-C and
+	# C++ because vllm.cpp appends target-local -Werror after these global flags.
 	CMAKE_ARGS+=-DCMAKE_CXX_FLAGS=-Wno-gnu-folding-constant
+	CMAKE_ARGS+=-DCMAKE_OBJC_FLAGS=-Wno-gnu-folding-constant
 	CMAKE_ARGS+=-DCMAKE_OBJCXX_FLAGS=-Wno-gnu-folding-constant
 else
 	LIB=libvllm.so