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 47c2a6f81..ee625b7c5 100644
--- a/model/URLSegmentFilter.php
+++ b/model/URLSegmentFilter.php
@@ -64,13 +64,17 @@ class URLSegmentFilter extends Object {
 		
 		$name = mb_strtolower($name);
 		$replacements = $this->getReplacements();
-		if($this->getAllowMultibyte()) {
-			// unset automated removal of non-ASCII characters, and don't try to transliterate
-			if(isset($replacements['/[^A-Za-z0-9+.-]+/u'])) unset($replacements['/[^A-Za-z0-9+.-]+/u']);
-		}
+		
+		// Unset automated removal of non-ASCII characters, and don't try to transliterate
+		if($this->getAllowMultibyte() && isset($replacements['/[^A-Za-z0-9+.-]+/u'])) unset($replacements['/[^A-Za-z0-9+.-]+/u']);
+		
 		foreach($replacements as $regex => $replace) {
 			$name = preg_replace($regex, $replace, $name);
 		}
+
+		// Multibyte URLs require percent encoding to comply to RFC 3986.
+		// Without this setting, the "remove non-ASCII chars" regex takes care of that.
+		if($this->getAllowMultibyte()) $name = rawurlencode($name);
 		
 		return $name;
 	}
diff --git a/static-main.php b/static-main.php
index a3f4ed8ff..339603573 100644
--- a/static-main.php
+++ b/static-main.php
@@ -83,9 +83,11 @@ if (
 		$file = isset($homepageMap[$_SERVER['HTTP_HOST']]) ? $homepageMap[$_SERVER['HTTP_HOST']] : $file;
 	}
 	
+	// Encode each part of the path individually, in order to support multibyte paths.
+	// SiteTree.URLSegment and hence the static folder and filenames are stored in encoded form,
+	// to avoid filesystem incompatibilities.
+	$file = implode('/', array_map('rawurlencode', explode('/', $file)));
 	// Find file by extension (either *.html or *.php)
-	$file = preg_replace('/[^a-zA-Z0-9\/\-_]/si', '-', $file);
-
 	if (file_exists($cacheBaseDir . $cacheDir . $file . '.html')) {
 		header('X-SilverStripe-Cache: hit at '.@date('r'));
 		echo file_get_contents($cacheBaseDir . $cacheDir . $file . '.html');
diff --git a/tests/core/ConvertTest.php b/tests/core/ConvertTest.php
index c4f69c741..859b02dc2 100644
--- a/tests/core/ConvertTest.php
+++ b/tests/core/ConvertTest.php
@@ -116,10 +116,13 @@ class ConvertTest extends SapphireTest {
 	 * @todo test toASCII()
 	 */
 	function testRaw2URL() {
+		$orig = URLSegmentFilter::$default_allow_multibyte;
+		URLSegmentFilter::$default_allow_multibyte = false;
 		$this->assertEquals('foo', Convert::raw2url('foo'));
 		$this->assertEquals('foo-and-bar', Convert::raw2url('foo & bar'));
 		$this->assertEquals('foo-and-bar', Convert::raw2url('foo & bar!'));
 		$this->assertEquals('foos-bar-2', Convert::raw2url('foo\'s [bar] (2)'));
+		URLSegmentFilter::$default_allow_multibyte = $orig;
 	}
 
 }
diff --git a/tests/model/URLSegmentFilterTest.php b/tests/model/URLSegmentFilterTest.php
index 3c0a263e8..79574f90a 100644
--- a/tests/model/URLSegmentFilterTest.php
+++ b/tests/model/URLSegmentFilterTest.php
@@ -27,7 +27,7 @@ class URLSegmentFilterTest extends SapphireTest {
 		$f = new URLSegmentFilter();
 		$f->setAllowMultibyte(true);
 		$this->assertEquals(
-			'brötchen', 
+			urlencode('brötchen'), 
 			$f->filter('Brötchen')
 		);
 	}