diff --git a/configure.ac b/configure.ac
index 645801b..3d5b5b0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -27,21 +27,21 @@ AC_SUBST([BASH_COMPLETION_DIR])
 AM_CONDITIONAL([ENABLE_BASH_COMPLETION],[test "x$with_bash_completion_dir" != "xno"])
 
 # Check for available terminal I/O speeds
-AC_CHECK_DECL([B57600], [AC_SUBST([B57600],["57600"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B115200], [AC_SUBST([B115200],["115200"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B230400], [AC_SUBST([B230400],["230400"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B460800], [AC_SUBST([B460800],["460800"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B500000], [AC_SUBST([B500000],["500000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B576000], [AC_SUBST([B576000],["576000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B921600], [AC_SUBST([B921600],["921600"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B1000000], [AC_SUBST([B1000000],["1000000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B1152000], [AC_SUBST([B1152000],["1152000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B1500000], [AC_SUBST([B1500000],["1500000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B2000000], [AC_SUBST([B2000000],["2000000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B2500000], [AC_SUBST([B2500000],["2500000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B3000000], [AC_SUBST([B3000000],["3000000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B3500000], [AC_SUBST([B3500000],["3500000"])], [], [[#include <termios.h>]])
-AC_CHECK_DECL([B4000000], [AC_SUBST([B4000000],["4000000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B57600], [AC_SUBST([B57600],["57600"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B115200], [AC_SUBST([B115200],["115200"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B230400], [AC_SUBST([B230400],["230400"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B460800], [AC_SUBST([B460800],["460800"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B500000], [AC_SUBST([B500000],["500000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B576000], [AC_SUBST([B576000],["576000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B921600], [AC_SUBST([B921600],["921600"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B1000000], [AC_SUBST([B1000000],["1000000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B1152000], [AC_SUBST([B1152000],["1152000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B1500000], [AC_SUBST([B1500000],["1500000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B2000000], [AC_SUBST([B2000000],["2000000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B2500000], [AC_SUBST([B2500000],["2500000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B3000000], [AC_SUBST([B3000000],["3000000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B3500000], [AC_SUBST([B3500000],["3500000"])], [], [[#include <termios.h>]])
+AC_CHECK_DECLS([B4000000], [AC_SUBST([B4000000],["4000000"])], [], [[#include <termios.h>]])
 
 AC_CONFIG_FILES([Makefile])
 AC_CONFIG_FILES([src/Makefile])
diff --git a/src/tty.c b/src/tty.c
index 7e2bf79..b94bef9 100644
--- a/src/tty.c
+++ b/src/tty.c
@@ -211,77 +211,77 @@ void tty_configure(void)
         case 38400:
             baudrate = B38400;
             break;
-#ifdef HAVE_DECL_B57600
+#if HAVE_DECL_B57600
         case 57600:
             baudrate = B57600;
             break;
 #endif
-#ifdef HAVE_DECL_B115200
+#if HAVE_DECL_B115200
         case 115200:
             baudrate = B115200;
             break;
 #endif
-#ifdef HAVE_DECL_B230400
+#if HAVE_DECL_B230400
         case 230400:
             baudrate = B230400;
             break;
 #endif
-#ifdef HAVE_DECL_B460800
+#if HAVE_DECL_B460800
         case 460800:
             baudrate = B460800;
             break;
 #endif
-#ifdef HAVE_DECL_B500000
+#if HAVE_DECL_B500000
         case 500000:
             baudrate = B500000;
             break;
 #endif
-#ifdef HAVE_DECL_B576000
+#if HAVE_DECL_B576000
         case 576000:
             baudrate = B576000;
             break;
 #endif
-#ifdef HAVE_DECL_B921600
+#if HAVE_DECL_B921600
         case 921600:
             baudrate = B921600;
             break;
 #endif
-#ifdef HAVE_DECL_B1000000
+#if HAVE_DECL_B1000000
         case 1000000:
             baudrate = B1000000;
             break;
 #endif
-#ifdef HAVE_DECL_B1152000
+#if HAVE_DECL_B1152000
         case 1152000:
             baudrate = B1152000;
             break;
 #endif
-#ifdef HAVE_DECL_B1500000
+#if HAVE_DECL_B1500000
         case 1500000:
             baudrate = B1500000;
             break;
 #endif
-#ifdef HAVE_DECL_B2000000
+#if HAVE_DECL_B2000000
         case 2000000:
             baudrate = B2000000;
             break;
 #endif
-#ifdef HAVE_DECL_B2500000
+#if HAVE_DECL_B2500000
         case 2500000:
             baudrate = B2500000;
             break;
 #endif
-#ifdef HAVE_DECL_B3000000
+#if HAVE_DECL_B3000000
         case 3000000:
             baudrate = B3000000;
             break;
 #endif
-#ifdef HAVE_DECL_B3500000
+#if HAVE_DECL_B3500000
         case 3500000:
             baudrate = B3500000;
             break;
 #endif
-#ifdef HAVE_DECL_B4000000
+#if HAVE_DECL_B4000000
         case 4000000:
             baudrate = B4000000;
             break;