--- a/configure.ac
+++ b/configure.ac
@@ -330,11 +330,13 @@
 
-AC_ARG_WITH(pam,
-    [  --with-pam     build with PAM support],
-    [AC_DEFINE([USE_PAM], 1, [Define to 1 to build with PAM support. (--with-pam)])])
-if test "$with_pam" = yes ; then
-   AC_CHECK_LIB(pam, pam_start, [], [AC_MSG_ERROR([library 'pam' is required for PAM])])
-   AC_CHECK_HEADERS(security/pam_appl.h, [],
-                    [AC_CHECK_HEADERS(pam/pam_appl.h, [],
-                                      [AC_MSG_ERROR([header file <security/pam_appl.h> or <pam/pam_appl.h> is required for PAM.])])])
-fi
+AC_ARG_WITH([pam], AS_HELP_STRING([--with-pam], [Build with PAM support]))
+
+AS_IF([test "x$with_pam" = "xyes"], [
+    AC_DEFINE([USE_PAM], 1, [Define to 1 to build with PAM support])
+    AC_CHECK_LIB(pam, pam_start, [], [AC_MSG_ERROR([library 'pam' is required for PAM])])
+    AC_CHECK_HEADERS(security/pam_appl.h,
+        [],
+        [AC_CHECK_HEADERS(pam/pam_appl.h, [],
+        [AC_MSG_ERROR([header file <security/pam_appl.h> or <pam/pam_appl.h> is required for PAM.])])])
+
+])