diff --git a/lib/Sabberworm/CSS/Value/Size.php b/lib/Sabberworm/CSS/Value/Size.php
index 05cf78c3..84628bf4 100644
--- a/lib/Sabberworm/CSS/Value/Size.php
+++ b/lib/Sabberworm/CSS/Value/Size.php
@@ -61,7 +61,7 @@ public function isRelative() {
 
 	public function __toString() {
 		$l = localeconv();
-		return str_replace(array($l['decimal_point'], '0.'), '.', $this->fSize) . ($this->sUnit === null ? '' : $this->sUnit);
+		return preg_replace(array('/' . preg_quote($l['decimal_point'], '/') . '/', '/^(-?)0\./'), '$1.', $this->fSize) . ($this->sUnit === null ? '' : $this->sUnit);
 	}
 
 }
diff --git a/tests/Sabberworm/CSS/RuleSet/LenientParsingTest.php b/tests/Sabberworm/CSS/RuleSet/LenientParsingTest.php
index a2d2b2fe..f2ddebd1 100644
--- a/tests/Sabberworm/CSS/RuleSet/LenientParsingTest.php
+++ b/tests/Sabberworm/CSS/RuleSet/LenientParsingTest.php
@@ -20,7 +20,7 @@ public function testFaultToleranceOn() {
 		$sFile = dirname(__FILE__) . '/../../../files' . DIRECTORY_SEPARATOR . "-fault-tolerance.css";
 		$oParser = new Parser(file_get_contents($sFile), Settings::create()->withLenientParsing(true));
 		$oResult = $oParser->parse();
-		$this->assertSame('.test1 {}'."\n".'.test2 {hello: 2.2;hello: 200000000000.2;}'."\n".'#test {}'."\n".'#test2 {help: none;}'."\n", $oResult->__toString());
+		$this->assertSame('.test1 {}'."\n".'.test2 {hello: 2.2;hello: 2000000000000.2;}'."\n".'#test {}'."\n".'#test2 {help: none;}'."\n", $oResult->__toString());
 	}
 	
 	/**
@@ -37,7 +37,7 @@ public function testLocaleTrap() {
 		$sFile = dirname(__FILE__) . '/../../../files' . DIRECTORY_SEPARATOR . "-fault-tolerance.css";
 		$oParser = new Parser(file_get_contents($sFile), Settings::create()->withLenientParsing(true));
 		$oResult = $oParser->parse();
-		$this->assertSame('.test1 {}'."\n".'.test2 {hello: 2.2;hello: 200000000000.2;}'."\n".'#test {}'."\n".'#test2 {help: none;}'."\n", $oResult->__toString());
+		$this->assertSame('.test1 {}'."\n".'.test2 {hello: 2.2;hello: 2000000000000.2;}'."\n".'#test {}'."\n".'#test2 {help: none;}'."\n", $oResult->__toString());
 	}
 
 	public function testCaseInsensitivity() {
diff --git a/tests/phpunit.xml b/tests/phpunit.xml
new file mode 100644
index 00000000..5dcbab2b
--- /dev/null
+++ b/tests/phpunit.xml
@@ -0,0 +1 @@
+<phpunit bootstrap="bootstrap.php"></phpunit>