diff --git a/src/os/windows/survey_win.cpp b/src/os/windows/survey_win.cpp
--- a/src/os/windows/survey_win.cpp
+++ b/src/os/windows/survey_win.cpp
@@ -10,15 +10,13 @@
 #include "../../stdafx.h"
 
 #include "../../3rdparty/fmt/format.h"
-#include "../../3rdparty/nlohmann/json.hpp"
+#include "../../survey.h"
 
 #include <thread>
 #include <windows.h>
 
 #include "../../safeguards.h"
 
-extern std::string SurveyMemoryToText(uint64_t memory);
-
 void SurveyOS(nlohmann::json &json)
 {
 	_OSVERSIONINFOA os;