diff --git a/configure.ac b/configure.ac
index feb6b7b47e5c8202880f1f0c652333c3bb5372ab..9ac76130640ad390357aae0f337e06ba5723c3cd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -64,12 +64,13 @@ AC_PREFIX_DEFAULT([`pwd`])
 AC_CHECK_LIB([m],[main],,
              [AC_MSG_ERROR([no math library, exiting...!])] )
 
-AC_CHECK_FUNCS([alarm pow sqrt strdup strchr strstr unsetenv],,
+AC_CHECK_FUNCS([alarm pow sqrt strdup strchr strstr],,
 	       [AC_MSG_ERROR([Sorry, these are needed..])])
 
 AC_FUNC_MALLOC
 AC_FUNC_VPRINTF
 
+AC_CHECK_FUNCS([unsetenv])
 AC_CHECK_FUNCS([getopt_long],[],
 	[AC_LIBOBJ([getopt])
 	AC_LIBOBJ([getopt1])