diff --git a/graphics/nxmu/nxmu_server.c b/graphics/nxmu/nxmu_server.c
index 52c409caa60..eb7fbd75ca5 100644
--- a/graphics/nxmu/nxmu_server.c
+++ b/graphics/nxmu/nxmu_server.c
@@ -291,9 +291,9 @@ static inline int nxmu_setup(FAR const char *mqname, FAR NX_DRIVERTYPE *dev,
 
 int nx_runinstance(FAR const char *mqname, FAR NX_DRIVERTYPE *dev)
 {
-  struct nxfe_state_s     fe;
+  struct nxfe_state_s    fe;
   FAR struct nxsvrmsg_s *msg;
-  uint8_t                buffer[NX_MXSVRMSGLEN];
+  char                   buffer[NX_MXSVRMSGLEN];
   int                    nbytes;
   int                    ret;
 
diff --git a/libnx/nxmu/nx_eventhandler.c b/libnx/nxmu/nx_eventhandler.c
index e9ba2a39ac6..71172fe6f97 100644
--- a/libnx/nxmu/nx_eventhandler.c
+++ b/libnx/nxmu/nx_eventhandler.c
@@ -138,7 +138,7 @@ int nx_eventhandler(NXHANDLE handle)
   FAR struct nxfe_conn_s *conn = (FAR struct nxfe_conn_s *)handle;
   struct nxsvrmsg_s      *msg;
   struct nxbe_window_s   *wnd;
-  uint8_t                 buffer[NX_MXCLIMSGLEN];
+  char                    buffer[NX_MXCLIMSGLEN];
   int                     nbytes;
 
   /* Get the next message from our incoming message queue */