diff --git a/daemon/lookup.c b/daemon/lookup.c

index fd99cf2..0be10d3 100644

--- a/daemon/lookup.c

+++ b/daemon/lookup.c

@@ -222,6 +222,28 @@ int lookup_nss_read_master(struct master *master, time_t age)

 		      "reading master %s %s", this->source, master->name);

 		result = read_master_map(master, this->source, age);

+

+		/*

+		 * If the name of the master map hasn't been explicitly

+		 * configured and we're not reading an included master map

+		 * then we're using auto.master as the default. Many setups

+		 * also use auto_master as the default master map so we

+		 * check for this map when auto.master isn't found.

+		 */

+		if (result != NSS_STATUS_SUCCESS &&

+		    !master->depth && !defaults_master_set()) {

+			char *tmp = strchr(master->name, '.');

+			if (tmp) {

+				debug(logopt,

+				      "%s not found, replacing '.' with '_'",

+				       master->name);

+				*tmp = '_';

+				result = read_master_map(master, this->source, age);

+				if (result != NSS_STATUS_SUCCESS)

+					*tmp = '.';

+			}

+		}

+

 		if (result == NSS_STATUS_UNKNOWN) {

 			debug(logopt, "no map - continuing to next source");

 			continue;

diff --git a/include/defaults.h b/include/defaults.h

index 0e0e2a5..e296478 100644

--- a/include/defaults.h

+++ b/include/defaults.h

@@ -43,6 +43,7 @@ struct ldap_searchdn;

 unsigned int defaults_read_config(unsigned int);

 const char *defaults_get_master_map(void);

+int defaults_master_set(void);

 unsigned int defaults_get_timeout(void);

 unsigned int defaults_get_browse_mode(void);

 unsigned int defaults_get_logging(void);

diff --git a/lib/defaults.c b/lib/defaults.c

index 94885e8..f494103 100644

--- a/lib/defaults.c

+++ b/lib/defaults.c

@@ -350,6 +350,15 @@ const char *defaults_get_master_map(void)

 	return (const char *) master;

 }

+int defaults_master_set(void)

+{

+	char *val = getenv(ENV_NAME_MASTER_MAP);

+	if (!val)

+		return 0;

+

+	return 1;

+}

+

 unsigned int defaults_get_timeout(void)

 {

 	long timeout;