diff --git a/plugins/zerospu2/Windows/Win32.cpp b/plugins/zerospu2/Windows/Win32.cpp
index 7cf5a8f867..d2017fecf1 100644
--- a/plugins/zerospu2/Windows/Win32.cpp
+++ b/plugins/zerospu2/Windows/Win32.cpp
@@ -30,7 +30,7 @@ extern HWND hWMain;
 /////////
 HINSTANCE hInst;
 
-void SysMessage(char *fmt, ...)
+void SysMessage(const char *fmt, ...)
 {
 	va_list list;
 	char tmp[512];
diff --git a/plugins/zerospu2/zerodma.cpp b/plugins/zerospu2/zerodma.cpp
index f16e435d8d..4b6e923723 100644
--- a/plugins/zerospu2/zerodma.cpp
+++ b/plugins/zerospu2/zerodma.cpp
@@ -30,7 +30,7 @@ void CALLBACK SPU2readDMAMem(u16 *pMem, int size, int channel)
 
 	SPU2_LOG("SPU2 readDMAMem(%d) size %x, addr: %x\n", channel,  size, pMem);
 
-	for (u32 i = 0; i < size; i++)
+	for (uint i = 0; i < (uint)size; i++)
 	{
 		*pMem++ = *(u16*)(spu2mem + spuaddr);
 		if (spu2attr(channel).irq && (C_IRQA(channel) == spuaddr))
diff --git a/plugins/zerospu2/zerospu2.h b/plugins/zerospu2/zerospu2.h
index 05290655ee..17168c5416 100644
--- a/plugins/zerospu2/zerospu2.h
+++ b/plugins/zerospu2/zerospu2.h
@@ -117,11 +117,11 @@ typedef struct {
 
 extern Config conf;
 
-void __Log(char *fmt, ...);
-void __LogToConsole(const char *fmt, ...);
-void SaveConfig();
-void LoadConfig();
-void SysMessage(const char *fmt, ...);
+extern void __Log(char *fmt, ...);
+extern void __LogToConsole(const char *fmt, ...);
+extern void SaveConfig();
+extern void LoadConfig();
+extern void SysMessage(const char *fmt, ...);
 
 extern void LogRawSound(void* pleft, int leftstride, void* pright, int rightstride, int numsamples);
 extern void LogPacketSound(void* packet, int memsize);