diff -Naur cyrus-sasl-2.1.18-orig/saslauthd/auth_pam.c cyrus-sasl-2.1.18/saslauthd/auth_pam.c
--- cyrus-sasl-2.1.18-orig/saslauthd/auth_pam.c	2003-05-31 13:00:24.000000000 -0400
+++ cyrus-sasl-2.1.18/saslauthd/auth_pam.c	2004-07-06 23:13:06.303220973 -0400
@@ -178,7 +178,7 @@
   const char *login,			/* I: plaintext authenticator */
   const char *password,			/* I: plaintext password */
   const char *service,			/* I: service name */
-  const char *realm __attribute__((unused))
+  const char *realm
   /* END PARAMETERS */
   )
 {
@@ -186,17 +186,25 @@
     pam_appdata my_appdata;		/* application specific data */
     struct pam_conv my_conv;		/* pam conversion data */
     pam_handle_t *pamh;			/* pointer to PAM handle */
+    char user[256];
     int rc;				/* return code holder */
     /* END VARIABLES */
 
-    my_appdata.login = login;
+    strlcpy(user, login, 256);
+
+    if (realm) {
+	    strlcat(user, "@", 256);
+	    strlcat(user, realm, 256);
+    }
+
+    my_appdata.login = user;
     my_appdata.password = password;
     my_appdata.pamh = NULL;
 
     my_conv.conv = saslauthd_pam_conv;
     my_conv.appdata_ptr = &my_appdata;
 
-    rc = pam_start(service, login, &my_conv, &pamh);
+    rc = pam_start(service, user, &my_conv, &pamh);
     if (rc != PAM_SUCCESS) {
 	syslog(LOG_DEBUG, "DEBUG: auth_pam: pam_start failed: %s",
 	       pam_strerror(pamh, rc));