diff --git a/Source/Core/Core/Src/HW/WiimoteReal/IOWin.cpp b/Source/Core/Core/Src/HW/WiimoteReal/IOWin.cpp
index 77555bae86..1d82a19e1a 100644
--- a/Source/Core/Core/Src/HW/WiimoteReal/IOWin.cpp
+++ b/Source/Core/Core/Src/HW/WiimoteReal/IOWin.cpp
@@ -73,7 +73,7 @@ HINSTANCE bthprops_lib = NULL;
 
 static int initialized = 0;
 
-int PairUp(bool unpair);
+int PairUp(bool unpair = false);
 
 inline void init_lib()
 {