diff --git a/apu/bapu/smp/core.cpp b/apu/bapu/smp/core.cpp
index 5303bed7..b46041b4 100644
--- a/apu/bapu/smp/core.cpp
+++ b/apu/bapu/smp/core.cpp
@@ -51,8 +51,8 @@ void SMP::op_write(uint16 addr, uint8 data) {
 
 void SMP::op_step() {
   #define op_readpc() op_read(regs.pc++)
-  #define op_readdp(addr) op_read((regs.p.p << 8) + (addr & 0xff))
-  #define op_writedp(addr, data) op_write((regs.p.p << 8) + (addr & 0xff), data)
+  #define op_readdp(addr) op_read((regs.p.p << 8) + ((addr) & 0xff))
+  #define op_writedp(addr, data) op_write((regs.p.p << 8) + ((addr) & 0xff), data)
   #define op_readaddr(addr) op_read(addr)
   #define op_writeaddr(addr, data) op_write(addr, data)
   #define op_readstack() op_read(0x0100 | ++regs.sp)
diff --git a/loadzip.cpp b/loadzip.cpp
index 840da42e..56e65b67 100644
--- a/loadzip.cpp
+++ b/loadzip.cpp
@@ -270,7 +270,7 @@ bool8 LoadZip (const char *zipname, uint32 *TotalFileSize, uint8 *buffer)
 	uint8	*ptr = buffer;
 	bool8	more = FALSE;
 
-	unzLocateFile(file, filename, NULL);
+	unzLocateFile(file, filename, 0);
 	unzGetCurrentFileInfo(file, &info, filename, 128, NULL, 0, NULL, 0);
 
 	if (unzOpenCurrentFile(file) != UNZ_OK)
@@ -330,7 +330,7 @@ bool8 LoadZip (const char *zipname, uint32 *TotalFileSize, uint8 *buffer)
 
 		if (more)
 		{
-			if (unzLocateFile(file, filename, NULL) != UNZ_OK ||
+			if (unzLocateFile(file, filename, 0) != UNZ_OK ||
 				unzGetCurrentFileInfo(file, &info, filename, 128, NULL, 0, NULL, 0) != UNZ_OK ||
 				unzOpenCurrentFile(file) != UNZ_OK)
 				break;
diff --git a/msu1.cpp b/msu1.cpp
index 341f5226..f857000d 100644
--- a/msu1.cpp
+++ b/msu1.cpp
@@ -240,7 +240,7 @@ static int unzFindExtension(unzFile &file, const char *ext, bool restart = TRUE,
 }
 #endif
 
-STREAM S9xMSU1OpenFile(char *msu_ext, bool skip_unpacked)
+STREAM S9xMSU1OpenFile(const char *msu_ext, bool skip_unpacked)
 {
     const char *filename = S9xGetFilename(msu_ext, ROMFILENAME_DIR);
 	STREAM file = 0;
diff --git a/msu1.h b/msu1.h
index e51739b0..1e6ea15f 100644
--- a/msu1.h
+++ b/msu1.h
@@ -229,7 +229,7 @@ extern struct SMSU1	MSU1;
 void S9xResetMSU(void);
 void S9xMSU1Init(void);
 bool S9xMSU1ROMExists(void);
-STREAM S9xMSU1OpenFile(char *msu_ext, bool skip_unpacked = FALSE);
+STREAM S9xMSU1OpenFile(const char *msu_ext, bool skip_unpacked = FALSE);
 void S9xMSU1Init(void);
 void S9xMSU1Generate(size_t sample_count);
 uint8 S9xMSU1ReadPort(uint8 port);