diff -up setserial-2.17/setserial.c.hayesesp setserial-2.17/setserial.c
--- setserial-2.17/setserial.c.hayesesp	2010-02-15 12:20:59.104048442 +0000
+++ setserial-2.17/setserial.c	2010-02-15 12:21:42.368924088 +0000
@@ -356,7 +356,7 @@ void set_multiport(char *device, int fd,
 }
 #endif
 
-#ifdef TIOCGHAYESESP
+#if defined(TIOCGHAYESESP) && defined(HAVE_LINUX_HAYESESP_H)
 void print_hayesesp(int fd)
 {
 	struct hayes_esp_config esp;
@@ -453,7 +453,7 @@ void get_serial(char *device)
 		print_flags(&serinfo, "\tFlags: ", "");
 		printf("\n\n");
 
-#ifdef TIOCGHAYESESP
+#if defined(TIOCGHAYESESP) && defined(HAVE_LINUX_HAYESESP_H)
 		print_hayesesp(fd);
 #endif
 	} else if (verbosity==0) {
@@ -593,7 +593,7 @@ void set_serial(char *device, char ** ar
 			}
 			set_multiport(device, fd, &arg);
 			break;
-#ifdef TIOCGHAYESESP
+#if defined(TIOCGHAYESESP) && defined(HAVE_LINUX_HAYESESP_H)
 		case CMD_RX_TRIG:
 		case CMD_TX_TRIG:
 		case CMD_FLOW_OFF: