diff --git a/package/upx/upx.mk b/package/upx/upx.mk
index 400d28328d..eaef27590a 100644
--- a/package/upx/upx.mk
+++ b/package/upx/upx.mk
@@ -17,6 +17,7 @@ HOST_UPX_DEPENDENCIES = host-ucl host-zlib
 define HOST_UPX_BUILD_CMDS
 	$(HOST_MAKE_ENV) $(MAKE) CPPFLAGS="$(HOST_CPPFLAGS)" \
 		LDFLAGS="$(HOST_LDFLAGS)" UPX_UCLDIR=$(HOST_DIR)/usr \
+		CXXFLAGS_WERROR= \
 		-C $(@D) all
 endef