--- configure.ac
+++ configure.ac
@@ -51,6 +51,11 @@
 # Checks for libraries.
 #
 
+dnl Check for libm for ceil()
+AC_SEARCH_LIBS([ceil], [m], [], [
+	AC_MSG_ERROR([unable to find the ceil() function])
+])
+
 # check for libcurl.
 AC_ARG_WITH([curl-config],
  AC_HELP_STRING([--with-curl-config=PATH], [path to curl-config (e.g. /opt/bin)]),