diff --git a/examples/chat/chat_main.c b/examples/chat/chat_main.c
index 35390793d..fe791bd29 100644
--- a/examples/chat/chat_main.c
+++ b/examples/chat/chat_main.c
@@ -74,7 +74,7 @@ struct chat_app
   int argc;                        /* number of command-line arguments */
   FAR char** argv;                 /* command-line arguments */
   char tty[CHAT_TTYNAME_SIZE];     /* modem TTY device node */
-  FAR char* script;                /* raw chat script - input to the parser */
+  FAR const char *script;          /* raw chat script - input to the parser */
   bool script_dynalloc;            /* true iff the script should be freed */
 };
 
@@ -84,10 +84,10 @@ struct chat_app
 
 /* Preset chat scripts */
 
-FAR char g_chat_script0[] = CONFIG_EXAMPLES_CHAT_PRESET0;
-FAR char g_chat_script1[] = CONFIG_EXAMPLES_CHAT_PRESET1;
-FAR char g_chat_script2[] = CONFIG_EXAMPLES_CHAT_PRESET2;
-FAR char g_chat_script3[] = CONFIG_EXAMPLES_CHAT_PRESET3;
+FAR const char g_chat_script0[] = CONFIG_EXAMPLES_CHAT_PRESET0;
+FAR const char g_chat_script1[] = CONFIG_EXAMPLES_CHAT_PRESET1;
+FAR const char g_chat_script2[] = CONFIG_EXAMPLES_CHAT_PRESET2;
+FAR const char g_chat_script3[] = CONFIG_EXAMPLES_CHAT_PRESET3;
 
 /****************************************************************************
  * Private Functions
@@ -105,7 +105,7 @@ static void chat_show_usage(void)
          "-v         : verbose mode\n");
 }
 
-static int chat_chardev(FAR struct chat_app* priv)
+static int chat_chardev(FAR struct chat_app *priv)
 {
   int flags;
 
@@ -124,7 +124,7 @@ static int chat_chardev(FAR struct chat_app* priv)
   return 0;
 }
 
-static int chat_script_preset(FAR struct chat_app* priv, int script_number)
+static int chat_script_preset(FAR struct chat_app *priv, int script_number)
 {
   int ret = 0;
 
@@ -159,21 +159,21 @@ static int chat_script_preset(FAR struct chat_app* priv, int script_number)
 static int chat_script_read(FAR struct chat_app* priv,
                             FAR const char* filepath)
 {
-  FAR char* scriptp;
-  size_t spare_size = CONFIG_EXAMPLES_CHAT_SIZE-1;
+  FAR char *scriptp;
+  size_t spare_size = CONFIG_EXAMPLES_CHAT_SIZE - 1;
   ssize_t read_size;
   bool eof = false;
   int ret = 0;
   int fd;
 
-  priv->script = malloc(CONFIG_EXAMPLES_CHAT_SIZE);
-  if (!priv->script)
+  scriptp = malloc(CONFIG_EXAMPLES_CHAT_SIZE);
+  if (scriptp == NULL)
     {
       return -ENOMEM;
     }
 
   priv->script_dynalloc = true;
-  scriptp = priv->script;
+  priv->script          = scriptp;
   memset(scriptp, 0, CONFIG_EXAMPLES_CHAT_SIZE);
 
   fd = open(filepath, O_RDONLY);
@@ -219,8 +219,7 @@ static int chat_script_read(FAR struct chat_app* priv,
 
 static int chat_parse_args(FAR struct chat_app* priv)
 {
-  /*
-   * -d TTY device node (non-Linux feature)
+  /* -d TTY device node (non-Linux feature)
    * -e echo to stderr
    * -f script file
    * -p preprogrammed script (non-Linux feature)
@@ -383,7 +382,7 @@ with_tty_dev:
 with_script:
   if (priv.script_dynalloc)
     {
-      free(priv.script);
+      free((FAR char *)priv.script);
     }
 
 no_script:
diff --git a/include/netutils/chat.h b/include/netutils/chat.h
index b86641250..b1ff0a5c3 100644
--- a/include/netutils/chat.h
+++ b/include/netutils/chat.h
@@ -69,7 +69,7 @@ extern "C"
 #define EXTERN extern
 #endif
 
-int chat(FAR struct chat_ctl* ctl, FAR char* script);
+int chat(FAR struct chat_ctl *ctl, FAR const char *script);
 
 #undef EXTERN
 #ifdef __cplusplus
diff --git a/netutils/chat/chat.c b/netutils/chat/chat.c
index c837ccaf5..f2b7949ba 100644
--- a/netutils/chat/chat.c
+++ b/netutils/chat/chat.c
@@ -75,7 +75,7 @@ struct chat_token
  * Private Functions
  ****************************************************************************/
 
-void chat_init(FAR struct chat* priv, FAR struct chat_ctl* ctl)
+void chat_init(FAR struct chat *priv, FAR struct chat_ctl *ctl)
 {
   DEBUGASSERT(priv != NULL && ctl != NULL && ctl->timeout >= 0);
 
@@ -85,20 +85,20 @@ void chat_init(FAR struct chat* priv, FAR struct chat_ctl* ctl)
 
 /* Linear one-pass tokenizer. */
 
-static int chat_tokenise(FAR struct chat* priv,
-                         FAR char* script,
-                         FAR struct chat_token** first_tok)
+static int chat_tokenise(FAR struct chat *priv,
+                         FAR const char *script,
+                         FAR struct chat_token **first_tok)
 {
-  FAR char *cursor = script;     /* pointer to the current character */
-  unsigned int quoted = 0;       /* two-valued:
-                                  * 1: quoted (expecting a closing quote)
-                                  * 0: not quoted */
-  unsigned int escaped = 0;      /* two-valued */
-  char tok_str[CHAT_TOKEN_SIZE]; /* current token buffer */
-  int tok_pos = 0;               /* current length of the current token */
+  FAR const char *cursor = script;   /* pointer to the current character */
+  unsigned int quoted = 0;           /* two-valued:
+                                      * 1: quoted (expecting a closing quote)
+                                      * 0: not quoted */
+  unsigned int escaped = 0;          /* two-valued */
+  char tok_str[CHAT_TOKEN_SIZE];     /* current token buffer */
+  int tok_pos = 0;                   /* current length of the current token */
   FAR struct chat_token *tok = NULL; /* the last complete token */
-  bool no_termin;                /* line termination property:
-                                  * true iff line terminator is deasserted */
+  bool no_termin;                    /* line termination property:
+                                      * true iff line terminator is deasserted */
   int ret = 0;
 
   /* Delimiter handler */
@@ -285,12 +285,12 @@ static int chat_tokenise(FAR struct chat* priv,
 
 /* Creates the internal representation of a tokenised chat script. */
 
-static int chat_internalise(FAR struct chat* priv,
-                            FAR struct chat_token* tok)
+static int chat_internalise(FAR struct chat *priv,
+                            FAR struct chat_token *tok)
 {
   unsigned int rhs = 0;  /* 1 iff processing the right-hand side,
                           * 0 otherwise */
-  FAR struct chat_line* line = NULL;
+  FAR struct chat_line *line = NULL;
   int len; /* length of the destination string when variable */
   int ret = 0;
 
@@ -412,7 +412,7 @@ static int chat_internalise(FAR struct chat* priv,
 
 /* Chat token list deallocator */
 
-static void chat_tokens_free(FAR struct chat_token* first_tok)
+static void chat_tokens_free(FAR struct chat_token *first_tok)
 {
   FAR struct chat_token* next_tok;
 
@@ -431,9 +431,9 @@ static void chat_tokens_free(FAR struct chat_token* first_tok)
 
 /* Main parsing function. */
 
-static int chat_script_parse(FAR struct chat* priv, FAR char* script)
+static int chat_script_parse(FAR struct chat *priv, FAR const char *script)
 {
-  FAR struct chat_token* first_tok;
+  FAR struct chat_token *first_tok;
   int ret;
 
   ret = chat_tokenise(priv, script, &first_tok);
@@ -451,7 +451,7 @@ static int chat_script_parse(FAR struct chat* priv, FAR char* script)
  * returns a negative error code.
  */
 
-static int chat_readb(FAR struct chat* priv, FAR char* c, int timeout_ms)
+static int chat_readb(FAR struct chat *priv, FAR char *c, int timeout_ms)
 {
   struct pollfd fds;
   int ret;
@@ -483,16 +483,16 @@ static int chat_readb(FAR struct chat* priv, FAR char* c, int timeout_ms)
   return 0;
 }
 
-static void chat_flush(FAR struct chat* priv)
+static void chat_flush(FAR struct chat *priv)
 {
   char c;
 
   _info("starting\n");
-  while (chat_readb(priv, (FAR char*) &c, 0) == 0);
+  while (chat_readb(priv, (FAR char *) &c, 0) == 0);
   _info("done\n");
 }
 
-static int chat_expect(FAR struct chat* priv, FAR const char* s)
+static int chat_expect(FAR struct chat *priv, FAR const char *s)
 {
   char c;
   struct timespec abstime;
@@ -545,7 +545,7 @@ static int chat_expect(FAR struct chat* priv, FAR const char* s)
   return ret;
 }
 
-static int chat_send(FAR struct chat* priv, FAR const char* s)
+static int chat_send(FAR struct chat *priv, FAR const char *s)
 {
   int ret = 0;
   int len = strlen(s);
@@ -658,9 +658,9 @@ static int chat_line_run(FAR struct chat* priv,
   return ret;
 }
 
-static int chat_script_run(FAR struct chat* priv)
+static int chat_script_run(FAR struct chat *priv)
 {
-  FAR struct chat_line* line = priv->script;
+  FAR struct chat_line *line = priv->script;
   int ret = 0;
 #ifdef CONFIG_DEBUG_INFO
   int line_num = 0;
@@ -682,7 +682,7 @@ static int chat_script_run(FAR struct chat* priv)
   return ret;
 }
 
-static int chat_script_free(FAR struct chat* priv)
+static int chat_script_free(FAR struct chat *priv)
 {
   FAR struct chat_line* line = priv->script;
   FAR struct chat_line* next_line;
@@ -709,7 +709,7 @@ static int chat_script_free(FAR struct chat* priv)
  * Public Functions
  ****************************************************************************/
 
-int chat(FAR struct chat_ctl* ctl, FAR char* script)
+int chat(FAR struct chat_ctl *ctl, FAR const char *script)
 {
   int ret = 0;
   struct chat priv;