diff --git a/sc2/src/sc2code/libs/compiler.h b/sc2/src/sc2code/libs/compiler.h
index 92282ab22..d62e6893d 100644
--- a/sc2/src/sc2code/libs/compiler.h
+++ b/sc2/src/sc2code/libs/compiler.h
@@ -37,6 +37,7 @@ typedef SDWORD          *PSDWORD;
 typedef SBYTE           *PSTR;
 
 typedef void            *PVOID;
+typedef const void     *PCVOID;
 
 typedef UWORD             COUNT;
 typedef COUNT           *PCOUNT;
diff --git a/sc2/src/sc2code/libs/reslib.h b/sc2/src/sc2code/libs/reslib.h
index dec48dddf..846fc2129 100644
--- a/sc2/src/sc2code/libs/reslib.h
+++ b/sc2/src/sc2code/libs/reslib.h
@@ -56,7 +56,7 @@ const char *_cur_resfile_name;
 extern uio_Stream *res_OpenResFile (uio_DirHandle *dir, const char *filename,
 		const char *mode);
 extern int ReadResFile (PVOID lpBuf, COUNT size, COUNT count, uio_Stream *fp);
-extern int WriteResFile (PVOID lpBuf, COUNT size, COUNT count,
+extern int WriteResFile (PCVOID lpBuf, COUNT size, COUNT count,
 		uio_Stream *fp);
 extern int GetResFileChar (uio_Stream *fp);
 extern int PutResFileChar (char ch, uio_Stream *fp);
diff --git a/sc2/src/sc2code/libs/resource/filecntl.c b/sc2/src/sc2code/libs/resource/filecntl.c
index b229cd412..7453b0d07 100644
--- a/sc2/src/sc2code/libs/resource/filecntl.c
+++ b/sc2/src/sc2code/libs/resource/filecntl.c
@@ -71,7 +71,7 @@ ReadResFile (PVOID lpBuf, COUNT size, COUNT count, uio_Stream *fp)
 }
 
 int
-WriteResFile (PVOID lpBuf, COUNT size, COUNT count, uio_Stream *fp)
+WriteResFile (PCVOID lpBuf, COUNT size, COUNT count, uio_Stream *fp)
 {
 	int retval;