--- a/configure.in
+++ b/configure.in
@@ -11,11 +11,11 @@
 AC_PROG_LN_S
 
 dnl Checks for libraries.
-AC_CHECK_LIB(fltk,numericsort,,AC_MSG_ERROR("missing fltk"))
+AC_CHECK_LIB(fltk,fl_numericsort,,AC_MSG_ERROR("missing fltk"))
 AM_PATH_ALSA(0.9.0)
 
 dnl Checks for header files.
 AC_HEADER_STDC
-AC_HAVE_HEADERS(stdio.h string.h stdlib.h getopt.h alsa/asoundlib.h FL/Fl.H)
+AC_HAVE_HEADERS(stdio.h string.h stdlib.h getopt.h alsa/asoundlib.h)
 
 AC_OUTPUT(Makefile src/Makefile)