1 files changed, 1 insertions, 1 deletions

diff --git a/uisimulator/common/io.c b/uisimulator/common/io.c
index 56f1339fbc..3591905e32 100644
--- a/uisimulator/common/io.c
+++ b/uisimulator/common/io.c
@@ -526,7 +526,7 @@ int sim_fsync(int fd)
 
 #ifndef __PCTOOL__
 
-void *lc_open(const char *filename, char *buf, size_t buf_size)
+void *lc_open(const char *filename, unsigned char *buf, size_t buf_size)
 {
     const char *sim_path = get_sim_pathname(filename);
     void *handle = _lc_open(UTF8_TO_OS(sim_path), buf, buf_size);