diff --git a/Source/Core/Core/BootManager.cpp b/Source/Core/Core/BootManager.cpp
index b2d204e1f3..ee0365dd27 100644
--- a/Source/Core/Core/BootManager.cpp
+++ b/Source/Core/Core/BootManager.cpp
@@ -152,7 +152,8 @@ bool BootCore(const std::string& _rFilename)
 			int source;
 			for (unsigned int i = 0; i < MAX_WIIMOTES; ++i)
 			{
-				game_ini.Get("Controls", ("WiimoteSource" + std::to_string((long long) i)).c_str(), &source, -1);
+				std::string num = StringFromFormat("%u", i);
+				game_ini.Get("Controls", ("WiimoteSource" + num).c_str(), &source, -1);
 				if (source != -1 && g_wiimote_sources[i] != source && source >= WIIMOTE_SRC_NONE && source <= WIIMOTE_SRC_HYBRID)
 				{
 					config_cache.iSetWiimoteSource[i] = source;