Index: guile-1.8.1/configure.in
===================================================================
--- guile-1.8.1.orig/configure.in
+++ guile-1.8.1/configure.in
@@ -602,6 +602,7 @@ AC_CHECK_HEADERS([assert.h crt_externs.h
 #       (DINFINITY and DQNAN are actually global variables, not functions)
 #   chsize - an MS-DOS-ism, found in mingw
 #   clog10 - not in mingw (though others like clog and csqrt are)
+#   clog,cexp - not in FreeBSD (though others are, like cabs)
 #   fesetround - available in C99, but not older systems
 #   ftruncate - posix, but probably not older systems (current mingw
 #               has it as an inline for chsize)
@@ -614,7 +615,7 @@ AC_CHECK_HEADERS([assert.h crt_externs.h
 #   isblank - available as a GNU extension or in C99
 #   _NSGetEnviron - Darwin specific
 #
-AC_CHECK_FUNCS([DINFINITY DQNAN chsize clog10 ctermid fesetround ftime ftruncate fchown getcwd geteuid gettimeofday gmtime_r ioctl lstat mkdir mknod nice readdir_r readlink rename rmdir select setegid seteuid setlocale setpgid setsid sigaction siginterrupt stat64 strftime strptime symlink sync sysconf tcgetpgrp tcsetpgrp times uname waitpid strdup system usleep atexit on_exit chown link fcntl ttyname getpwent getgrent kill getppid getpgrp fork setitimer getitimer strchr strcmp index bcopy memcpy rindex truncate unsetenv isblank _NSGetEnviron])
+AC_CHECK_FUNCS([DINFINITY DQNAN chsize clog10 clog cexp ctermid fesetround ftime ftruncate fchown getcwd geteuid gettimeofday gmtime_r ioctl lstat mkdir mknod nice readdir_r readlink rename rmdir select setegid seteuid setlocale setpgid setsid sigaction siginterrupt stat64 strftime strptime symlink sync sysconf tcgetpgrp tcsetpgrp times uname waitpid strdup system usleep atexit on_exit chown link fcntl ttyname getpwent getgrent kill getppid getpgrp fork setitimer getitimer strchr strcmp index bcopy memcpy rindex truncate unsetenv isblank _NSGetEnviron])
 
 # Reasons for testing:
 #   netdb.h - not in mingw
Index: guile-1.8.1/libguile/numbers.c
===================================================================
--- guile-1.8.1.orig/libguile/numbers.c
+++ guile-1.8.1/libguile/numbers.c
@@ -6018,7 +6018,7 @@ SCM_DEFINE (scm_log, "log", 1, 0, 0,
 {
   if (SCM_COMPLEXP (z))
     {
-#if HAVE_COMPLEX_DOUBLE
+#if HAVE_COMPLEX_DOUBLE && HAVE_CLOG
       return scm_from_complex_double (clog (SCM_COMPLEX_VALUE (z)));
 #else
       double re = SCM_COMPLEX_REAL (z);
@@ -6084,7 +6084,7 @@ SCM_DEFINE (scm_exp, "exp", 1, 0, 0,
 {
   if (SCM_COMPLEXP (z))
     {
-#if HAVE_COMPLEX_DOUBLE
+#if HAVE_COMPLEX_DOUBLE && HAVE_CEXP
       return scm_from_complex_double (cexp (SCM_COMPLEX_VALUE (z)));
 #else
       return scm_c_make_polar (exp (SCM_COMPLEX_REAL (z)),