diff --git a/admin/environment.xml b/admin/environment.xml
index dd9f685f288..ce2a0f2f0bf 100644
--- a/admin/environment.xml
+++ b/admin/environment.xml
@@ -185,6 +185,8 @@
           <ON_CHECK message="ctyperecommended" />
         </FEEDBACK>
       </PHP_EXTENSION>
+      <PHP_EXTENSION name="pcre" level="required">
+      </PHP_EXTENSION>
     </PHP_EXTENSIONS>
     <CUSTOM_CHECKS>
       <CUSTOM_CHECK file="question/upgrade.php" function="question_check_no_rqp_questions" level="optional">
@@ -287,6 +289,8 @@
           <ON_CHECK message="splrequired" />
         </FEEDBACK>
       </PHP_EXTENSION>
+      <PHP_EXTENSION name="pcre" level="required">
+      </PHP_EXTENSION>
     </PHP_EXTENSIONS>
     <PHP_SETTINGS>
       <PHP_SETTING name="memory_limit" value="40M" level="required">