diff --git a/cohort/lib.php b/cohort/lib.php
index e33f77a..61c542b 100755
--- a/cohort/lib.php
+++ b/cohort/lib.php
@@ -268,7 +268,7 @@ class cohort_candidate_selector extends user_selector_base {
 
         if (!$this->is_validating()) {
             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
-            if ($potentialmemberscount > 100) {
+            if ($potentialmemberscount > user_selector_base::MAX_USERS_PER_PAGE) {
                 return $this->too_many_results($search, $potentialmemberscount);
             }
         }
@@ -330,7 +330,7 @@ class cohort_existing_selector extends user_selector_base {
 
         if (!$this->is_validating()) {
             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
-            if ($potentialmemberscount > 100) {
+            if ($potentialmemberscount > user_selector_base::MAX_USERS_PER_PAGE) {
                 return $this->too_many_results($search, $potentialmemberscount);
             }
         }
diff --git a/enrol/manual/locallib.php b/enrol/manual/locallib.php
index 2a25af7..b326520 100755
--- a/enrol/manual/locallib.php
+++ b/enrol/manual/locallib.php
@@ -64,7 +64,7 @@ class enrol_manual_potential_participant extends user_selector_base {
 
         if (!$this->is_validating()) {
             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
-            if ($potentialmemberscount > 100) {
+            if ($potentialmemberscount > user_selector_base::MAX_USERS_PER_PAGE) {
                 return $this->too_many_results($search, $potentialmemberscount);
             }
         }
@@ -127,7 +127,7 @@ class enrol_manual_current_participant extends user_selector_base {
 
         if (!$this->is_validating()) {
             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
-            if ($potentialmemberscount > 100) {
+            if ($potentialmemberscount > user_selector_base::MAX_USERS_PER_PAGE) {
                 return $this->too_many_results($search, $potentialmemberscount);
             }
         }
diff --git a/mnet/service/enrol/locallib.php b/mnet/service/enrol/locallib.php
index c54ea2d..9e330f2 100755
--- a/mnet/service/enrol/locallib.php
+++ b/mnet/service/enrol/locallib.php
@@ -493,7 +493,7 @@ class mnetservice_enrol_existing_users_selector extends user_selector_base {
 
         if (!$this->is_validating()) {
             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
-            if ($potentialmemberscount > 100) {
+            if ($potentialmemberscount > user_selector_base::MAX_USERS_PER_PAGE) {
                 return $this->too_many_results($search, $potentialmemberscount);
             }
         }
@@ -580,7 +580,7 @@ class mnetservice_enrol_potential_users_selector extends user_selector_base {
 
         if (!$this->is_validating()) {
             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
-            if ($potentialmemberscount > 100) {
+            if ($potentialmemberscount > user_selector_base::MAX_USERS_PER_PAGE) {
                 return $this->too_many_results($search, $potentialmemberscount);
             }
         }
diff --git a/user/selector/lib.php b/user/selector/lib.php
index 9dd55f6..e6979d0 100755
--- a/user/selector/lib.php
+++ b/user/selector/lib.php
@@ -36,6 +36,8 @@ define('USER_SELECTOR_DEFAULT_ROWS', 20);
  * specified.
  */
 abstract class user_selector_base {
+       const MAX_USERS_PER_PAGE = 100;
+
     /** @var string The control name (and id) in the HTML. */
     protected $name;
     /** @var array Extra fields to search on and return in addition to firstname and lastname. */