diff --git a/configure.ac b/configure.ac
index e938431..07bd952 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,12 +34,15 @@ AC_PATH_PROG(PKG_CONFIG, pkg-config, [AC_MSG_ERROR([pkg-config not found.])])
 # Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_STDBOOL
-AC_CHECK_HEADERS([stdio.h stdlib.h stdint.h stddef.h stdbool.h])
-AC_CHECK_FUNCS([strdup, usleep], [AC_DEFINE([_XOPEN_SOURCE], [600], [Enable POSIX extensions if present])])
+AC_CHECK_HEADERS([fcntl.h limits.h stdio.h stdlib.h stdint.h stddef.h stdbool.h sys/ioctl.h sys/param.h sys/time.h termios.h])
+AC_CHECK_FUNCS([bzero memmove memset select strdup strerror strstr strtol usleep],
+	       [AC_DEFINE([_XOPEN_SOURCE], [600], [Enable POSIX extensions if present])])
 
 AC_DEFINE(_NETBSD_SOURCE, 1, [Define on NetBSD to activate all library features])
 AC_DEFINE(_DARWIN_C_SOURCE, 1, [Define on Darwin to activate all library features])
 
+AC_FUNC_MALLOC
+
 # Checks for types
 AC_TYPE_SIZE_T
 AC_TYPE_UINT8_T
@@ -48,6 +51,8 @@ AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 AC_TYPE_INT32_T
 
+AC_TYPE_SIGNAL
+
 LIBNFC_CFLAGS='-I$(top_srcdir)/libnfc -I$(top_builddir)/include -I$(top_srcdir)/include'
 AC_SUBST(LIBNFC_CFLAGS)
 
diff --git a/m4/libnfc_check_libusb.m4 b/m4/libnfc_check_libusb.m4
index f2a9bab..fcece46 100644
--- a/m4/libnfc_check_libusb.m4
+++ b/m4/libnfc_check_libusb.m4
@@ -18,8 +18,6 @@ AC_DEFUN([LIBNFC_CHECK_LIBUSB],
       fi
     fi
 
-    AC_MSG_CHECKING(for libusb)
-  
     # Search using libusb-config
     if test x"$HAVE_LIBUSB" = "x0"; then
       AC_PATH_PROG(libusb_CONFIG,libusb-config)
@@ -40,10 +38,7 @@ AC_DEFUN([LIBNFC_CHECK_LIBUSB],
     fi
 
     if test x"$HAVE_LIBUSB" = "x0"; then
-      AC_MSG_RESULT(no)
       AC_MSG_ERROR([libusb is mandatory.])
-    else
-      AC_MSG_RESULT(yes)
     fi
 
     AC_SUBST(libusb_LIBS)