diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index d13506b598..ef72152bce 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -134,6 +134,7 @@
 		<li>[Fix] Fix bug in postgresql db layer for LIMIT ALL clauses (reported by JRSweets)</li>
 		<li>[Fix] Sort backups by date, newest first (Bug #14818)</li>
 		<li>[Fix] Prevent incomplete backups stored if option &quot;store and download&quot; is selected and admin cancel download by removing the option. (Bug #20325)</li>
+		<li>[Fix] Enforce correct case for template variables</li>
 		<li>[Change] Allow download of conflicting file for later reference in automatic updater</li>
 		<li>[Change] Default difference view is now 'inline' instead of 'side by side'</li>
 		<li>[Change] Added new option for merging differences to conflicting files in automatic updater</li>
@@ -877,4 +878,4 @@
 </div>
 
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/phpBB/includes/functions_template.php b/phpBB/includes/functions_template.php
index 46c7cedc01..42a5eb3248 100644
--- a/phpBB/includes/functions_template.php
+++ b/phpBB/includes/functions_template.php
@@ -256,19 +256,19 @@ class template_compile
 		// transform vars prefixed by L_ into their language variable pendant if nothing is set within the tpldata array
 		if (strpos($text_blocks, '{L_') !== false)
 		{
-			$text_blocks = preg_replace('#\{L_([a-z0-9\-_]*)\}#is', "<?php echo ((isset(\$this->_rootref['L_\\1'])) ? \$this->_rootref['L_\\1'] : ((isset(\$user->lang['\\1'])) ? \$user->lang['\\1'] : '{ \\1 }')); ?>", $text_blocks);
+			$text_blocks = preg_replace('#\{L_([A-Z0-9\-_]+)\}#', "<?php echo ((isset(\$this->_rootref['L_\\1'])) ? \$this->_rootref['L_\\1'] : ((isset(\$user->lang['\\1'])) ? \$user->lang['\\1'] : '{ \\1 }')); ?>", $text_blocks);
 		}
 
 		// Handle addslashed language variables prefixed with LA_
 		// If a template variable already exist, it will be used in favor of it...
 		if (strpos($text_blocks, '{LA_') !== false)
 		{
-			$text_blocks = preg_replace('#\{LA_([a-z0-9\-_]*)\}#is', "<?php echo ((isset(\$this->_rootref['LA_\\1'])) ? \$this->_rootref['LA_\\1'] : ((isset(\$this->_rootref['L_\\1'])) ? addslashes(\$this->_rootref['L_\\1']) : ((isset(\$user->lang['\\1'])) ? addslashes(\$user->lang['\\1']) : '{ \\1 }'))); ?>", $text_blocks);
+			$text_blocks = preg_replace('#\{LA_([A-Z0-9\-_]+)\}#', "<?php echo ((isset(\$this->_rootref['LA_\\1'])) ? \$this->_rootref['LA_\\1'] : ((isset(\$this->_rootref['L_\\1'])) ? addslashes(\$this->_rootref['L_\\1']) : ((isset(\$user->lang['\\1'])) ? addslashes(\$user->lang['\\1']) : '{ \\1 }'))); ?>", $text_blocks);
 		}
 
 		// Handle remaining varrefs
-		$text_blocks = preg_replace('#\{([a-z0-9\-_]+)\}#is', "<?php echo (isset(\$this->_rootref['\\1'])) ? \$this->_rootref['\\1'] : ''; ?>", $text_blocks);
-		$text_blocks = preg_replace('#\{\$([a-z0-9\-_]+)\}#is', "<?php echo (isset(\$this->_tpldata['DEFINE']['.']['\\1'])) ? \$this->_tpldata['DEFINE']['.']['\\1'] : ''; ?>", $text_blocks);
+		$text_blocks = preg_replace('#\{([A-Z0-9\-_]+)\}#', "<?php echo (isset(\$this->_rootref['\\1'])) ? \$this->_rootref['\\1'] : ''; ?>", $text_blocks);
+		$text_blocks = preg_replace('#\{\$([A-Z0-9\-_]+)\}#', "<?php echo (isset(\$this->_tpldata['DEFINE']['.']['\\1'])) ? \$this->_tpldata['DEFINE']['.']['\\1'] : ''; ?>", $text_blocks);
 
 		return;
 	}