diff --git a/c/os_sunos.c b/c/os_sunos.c
index d97a384..29ede45 100644
--- a/c/os_sunos.c
+++ b/c/os_sunos.c
@@ -1,3 +1,5 @@
+#include <sys/termios.h>
+
 #include <math.h>
 #include <setjmp.h>
 #include <stdarg.h>
@@ -14,3 +16,15 @@ char *get_exename(char *buf, size_t size)
     (void)size;
     return NULL;
 }
+
+void cfmakeraw(struct termios *t)
+{
+    t->c_iflag &= ~(IMAXBEL | IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR |
+                    IGNCR | ICRNL | IXON);
+    t->c_oflag &= ~OPOST;
+    t->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+    t->c_cflag &= ~(CSIZE | PARENB);
+    t->c_cflag |= CS8;
+    t->c_cc[VMIN] = 1;
+    t->c_cc[VTIME] = 0;
+}
diff --git a/c/os_unix.c b/c/os_unix.c
index 9a4d0b8..6354ee2 100644
--- a/c/os_unix.c
+++ b/c/os_unix.c
@@ -218,6 +218,8 @@ static void relocate_dir(value_t oldv, value_t newv)
 static struct termios term_mode_orig;
 static struct termios term_mode_raw;
 
+void cfmakeraw(struct termios *t);
+
 static void term_mode_init(void)
 {
     static int done;