diff --git a/control/HTTPResponse.php b/control/HTTPResponse.php
index e99fda44f..0b6e2b895 100644
--- a/control/HTTPResponse.php
+++ b/control/HTTPResponse.php
@@ -152,7 +152,7 @@ class SS_HTTPResponse {
 		$this->body = $body;
 		
 		// Set content-length in bytes. Use mbstring to avoid problems with mb_internal_encoding() and mbstring.func_overload
-		$this->headers['Content-Length'] = (function_exists('mb_strlen') ? mb_strlen($this->body,'8bit') : strlen($this->body));
+		$this->headers['Content-Length'] = mb_strlen($this->body,'8bit');
 	}
 	
 	function getBody() {
diff --git a/model/URLSegmentFilter.php b/model/URLSegmentFilter.php
index 5d64ddd45..47c2a6f81 100644
--- a/model/URLSegmentFilter.php
+++ b/model/URLSegmentFilter.php
@@ -62,7 +62,7 @@ class URLSegmentFilter extends Object {
 			if($transliterator) $name = $transliterator->toASCII($name);
 		}
 		
-		$name = (function_exists('mb_strtolower')) ? mb_strtolower($name) : strtolower($name);
+		$name = mb_strtolower($name);
 		$replacements = $this->getReplacements();
 		if($this->getAllowMultibyte()) {
 			// unset automated removal of non-ASCII characters, and don't try to transliterate