diff --git a/picocom.c b/picocom.c
index cb54762..c163d2e 100644
--- a/picocom.c
+++ b/picocom.c
@@ -130,7 +130,7 @@ const char *flow_str[] = {
 
 /* character mapping names */
 struct map_names_s {
-    char *name;
+    const char *name;
     int flag;
 } map_names[] = {
     { "crlf", M_CRLF },
@@ -154,7 +154,8 @@ struct map_names_s {
 int
 parse_map (char *s)
 {
-    char *m, *t;
+    const char *m;
+    char *t;
     int f, flags, i;
 
     flags = 0;
diff --git a/term.c b/term.c
index 76b38cc..8024017 100644
--- a/term.c
+++ b/term.c
@@ -403,7 +403,7 @@ term_exitfunc (void)
                 r = tcsetattr(term.fd[i], TCSANOW, &term.origtermios[i]);
             } while ( r < 0 && errno == EINTR );
             if ( r < 0 ) {
-                char *tname;
+                const char *tname;
 
                 tname = ttyname(term.fd[i]);
                 if ( ! tname ) tname = "UNKNOWN";
@@ -447,7 +447,7 @@ term_lib_init (void)
                     r = tcsetattr(term.fd[i], TCSANOW, &term.origtermios[i]);
                 } while ( r < 0 && errno == EINTR );
                 if ( r < 0 ) {
-                    char *tname;
+                    const char *tname;
 
                     tname = ttyname(term.fd[i]);
                     if ( ! tname ) tname = "UNKNOWN";