diff --git a/Source/exehead/util.c b/Source/exehead/util.c
index 6d6c9147..04186155 100644
--- a/Source/exehead/util.c
+++ b/Source/exehead/util.c
@@ -410,7 +410,7 @@ void NSISCALL mini_memcpy(void *out, const void *in, int len)
   }
 }
 
-DWORD NSISCALL remove_ro_attr(TCHAR *file)
+DWORD NSISCALL remove_ro_attr(LPCTSTR file)
 {
   const DWORD attr = GetFileAttributes(file);
   if (attr != INVALID_FILE_ATTRIBUTES)
diff --git a/Source/exehead/util.h b/Source/exehead/util.h
index 248f260c..cedde068 100644
--- a/Source/exehead/util.h
+++ b/Source/exehead/util.h
@@ -107,7 +107,7 @@ void NSISCALL validate_filename(TCHAR *fn);
 void NSISCALL MoveFileOnReboot(LPCTSTR pszExisting, LPCTSTR pszNew);
 
 void NSISCALL mini_memcpy(void *out, const void *in, int len);
-DWORD NSISCALL remove_ro_attr(TCHAR *file);
+DWORD NSISCALL remove_ro_attr(LPCTSTR file);
 
 enum myGetProcAddressFunctions {
   MGA_GetDiskFreeSpaceEx,