diff --git a/common.h b/common.h
index b6aadbb..7349ff0 100644
--- a/common.h
+++ b/common.h
@@ -59,4 +59,6 @@ extern struct hss_config {
     char *output_file;
 } *pconfig;
 
+extern int stdout_isatty;
+
 #endif //_HSS_COMMON_H_
diff --git a/executor.c b/executor.c
index f76fd57..ccde3ea 100644
--- a/executor.c
+++ b/executor.c
@@ -25,12 +25,8 @@ volatile int alive_children = 0;
 
 static void
 print_line(struct slot *pslot, int io_type, sstring buf, void *data) {
-    static int stdout_istty = -1;
-    if (stdout_istty == -1) {
-        stdout_istty = isatty(STDOUT_FILENO);
-    }
     FILE *output = (FILE *) data;
-    if (output == stdout && stdout_istty) {
+    if (output == stdout && stdout_isatty) {
         if (io_type == STDOUT_FILENO) {
             printf(ANSI_COLOR_GREEN "[O] %s -> " ANSI_COLOR_RESET, pslot->host);
         } else {
diff --git a/main.c b/main.c
index 6c3594c..001cd7c 100644
--- a/main.c
+++ b/main.c
@@ -28,6 +28,8 @@ struct hss_config *pconfig = NULL;
 
 bool enable_local = false;
 
+int stdout_isatty = -1;
+
 enum state {
     REMOTE,
     INNER,
@@ -54,11 +56,23 @@ static const char *
 get_prompt() {
     switch (running_state) {
         case REMOTE:
-            return ANSI_COLOR_BOLD "[remote] >>> " ANSI_COLOR_RESET;
+            if (stdout_isatty) {
+                return ANSI_COLOR_BOLD "[remote] >>> " ANSI_COLOR_RESET;
+            } else {
+                return "[remote] >>> ";
+            }
         case INNER:
-            return ANSI_COLOR_MAGENTA_BOLD "[inner] >>> " ANSI_COLOR_RESET;
+            if (stdout_isatty) {
+                return ANSI_COLOR_MAGENTA_BOLD "[inner] >>> " ANSI_COLOR_RESET;
+            } else {
+                return "[inner] >>> ";
+            }
         case LOCAL:
-            return ANSI_COLOR_CYAN_BOLD "[local] >>> " ANSI_COLOR_RESET;
+            if (stdout_isatty) {
+                return ANSI_COLOR_CYAN_BOLD "[local] >>> " ANSI_COLOR_RESET;
+            } else {
+                return "[local] >>> ";
+            }
         default:
             return "[unknown] >>> ";
     }
@@ -273,7 +287,7 @@ parse_opts(int argc, char **argv) {
     }
 
     if (argc == 0) {
-        if (!isatty(STDOUT_FILENO)) {
+        if (!stdout_isatty && isatty(STDIN_FILENO)) {
             usage("missing command parameter");
         }
         return;
@@ -290,6 +304,7 @@ main(int argc, char **argv) {
 
     slots = calloc(1, sizeof(struct slot));
     inner_commands = calloc(1, sizeof(struct command));
+    stdout_isatty = isatty(STDOUT_FILENO);
 
     /* Set the default locale values according to environment variables. */
     setlocale(LC_ALL, "");