diff --git a/Source/Core/Common/UPnP.cpp b/Source/Core/Common/UPnP.cpp
index cb4a51574c..bedecf9a43 100644
--- a/Source/Core/Common/UPnP.cpp
+++ b/Source/Core/Common/UPnP.cpp
@@ -7,15 +7,16 @@
 #include "Common/UPnP.h"
 
 #include "Common/Logging/Log.h"
-#include "Common/StringUtil.h"
 
 #include <array>
+#include <cstdlib>
 #include <cstring>
 #include <miniupnpc.h>
 #include <miniwget.h>
 #include <string>
 #include <thread>
 #include <upnpcommands.h>
+#include <vector>
 
 static UPNPUrls s_urls;
 static IGDdatas s_data;
@@ -108,7 +109,7 @@ static bool InitUPnP()
 // --
 static bool UnmapPort(const u16 port)
 {
-  std::string port_str = StringFromFormat("%d", port);
+  std::string port_str = std::to_string(port);
   UPNP_DeletePortMapping(s_urls.controlURL, s_data.first.servicetype, port_str.c_str(), "UDP",
                          nullptr);
 
@@ -122,7 +123,7 @@ static bool MapPort(const char* addr, const u16 port)
   if (s_mapped > 0)
     UnmapPort(s_mapped);
 
-  std::string port_str = StringFromFormat("%d", port);
+  std::string port_str = std::to_string(port);
   int result = UPNP_AddPortMapping(
       s_urls.controlURL, s_data.first.servicetype, port_str.c_str(), port_str.c_str(), addr,
       (std::string("dolphin-emu UDP on ") + addr).c_str(), "UDP", nullptr, nullptr);