diff --git a/src/Symfony/Component/Routing/Generator/UrlGenerator.php b/src/Symfony/Component/Routing/Generator/UrlGenerator.php
index 4d00f3a096..02a59a9253 100644
--- a/src/Symfony/Component/Routing/Generator/UrlGenerator.php
+++ b/src/Symfony/Component/Routing/Generator/UrlGenerator.php
@@ -181,59 +181,58 @@ class UrlGenerator implements UrlGeneratorInterface, ConfigurableRequirementsInt
         }
 
         $schemeAuthority = '';
-        if ($host = $this->context->getHost()) {
-            $scheme = $this->context->getScheme();
+        $host = $this->context->getHost();
+        $scheme = $this->context->getScheme();
 
-            if ($requiredSchemes) {
-                if (!in_array($scheme, $requiredSchemes, true)) {
-                    $referenceType = self::ABSOLUTE_URL;
-                    $scheme = current($requiredSchemes);
-                }
+        if ($requiredSchemes) {
+            if (!in_array($scheme, $requiredSchemes, true)) {
+                $referenceType = self::ABSOLUTE_URL;
+                $scheme = current($requiredSchemes);
             }
+        }
 
-            if ($hostTokens) {
-                $routeHost = '';
-                foreach ($hostTokens as $token) {
-                    if ('variable' === $token[0]) {
-                        if (null !== $this->strictRequirements && !preg_match('#^'.$token[2].'$#i'.(empty($token[4]) ? '' : 'u'), $mergedParams[$token[3]])) {
-                            if ($this->strictRequirements) {
-                                throw new InvalidParameterException(strtr($message, array('{parameter}' => $token[3], '{route}' => $name, '{expected}' => $token[2], '{given}' => $mergedParams[$token[3]])));
-                            }
-
-                            if ($this->logger) {
-                                $this->logger->error($message, array('parameter' => $token[3], 'route' => $name, 'expected' => $token[2], 'given' => $mergedParams[$token[3]]));
-                            }
-
-                            return;
+        if ($hostTokens) {
+            $routeHost = '';
+            foreach ($hostTokens as $token) {
+                if ('variable' === $token[0]) {
+                    if (null !== $this->strictRequirements && !preg_match('#^'.$token[2].'$#i'.(empty($token[4]) ? '' : 'u'), $mergedParams[$token[3]])) {
+                        if ($this->strictRequirements) {
+                            throw new InvalidParameterException(strtr($message, array('{parameter}' => $token[3], '{route}' => $name, '{expected}' => $token[2], '{given}' => $mergedParams[$token[3]])));
                         }
 
-                        $routeHost = $token[1].$mergedParams[$token[3]].$routeHost;
-                    } else {
-                        $routeHost = $token[1].$routeHost;
-                    }
-                }
+                        if ($this->logger) {
+                            $this->logger->error($message, array('parameter' => $token[3], 'route' => $name, 'expected' => $token[2], 'given' => $mergedParams[$token[3]]));
+                        }
 
-                if ($routeHost !== $host) {
-                    $host = $routeHost;
-                    if (self::ABSOLUTE_URL !== $referenceType) {
-                        $referenceType = self::NETWORK_PATH;
+                        return;
                     }
+
+                    $routeHost = $token[1].$mergedParams[$token[3]].$routeHost;
+                } else {
+                    $routeHost = $token[1].$routeHost;
                 }
             }
 
-            if (self::ABSOLUTE_URL === $referenceType || self::NETWORK_PATH === $referenceType) {
-                $port = '';
-                if ('http' === $scheme && 80 != $this->context->getHttpPort()) {
-                    $port = ':'.$this->context->getHttpPort();
-                } elseif ('https' === $scheme && 443 != $this->context->getHttpsPort()) {
-                    $port = ':'.$this->context->getHttpsPort();
+            if ($routeHost !== $host) {
+                $host = $routeHost;
+                if (self::ABSOLUTE_URL !== $referenceType) {
+                    $referenceType = self::NETWORK_PATH;
                 }
-
-                $schemeAuthority = self::NETWORK_PATH === $referenceType ? '//' : "$scheme://";
-                $schemeAuthority .= $host.$port;
             }
         }
 
+        if ((self::ABSOLUTE_URL === $referenceType || self::NETWORK_PATH === $referenceType) && !empty($host)) {
+            $port = '';
+            if ('http' === $scheme && 80 != $this->context->getHttpPort()) {
+                $port = ':'.$this->context->getHttpPort();
+            } elseif ('https' === $scheme && 443 != $this->context->getHttpsPort()) {
+                $port = ':'.$this->context->getHttpsPort();
+            }
+
+            $schemeAuthority = self::NETWORK_PATH === $referenceType ? '//' : "$scheme://";
+            $schemeAuthority .= $host.$port;
+        }
+
         if (self::RELATIVE_PATH === $referenceType) {
             $url = self::getRelativePath($this->context->getPathInfo(), $url);
         } else {
diff --git a/src/Symfony/Component/Routing/Tests/Generator/UrlGeneratorTest.php b/src/Symfony/Component/Routing/Tests/Generator/UrlGeneratorTest.php
index e334e437e1..68add771b7 100644
--- a/src/Symfony/Component/Routing/Tests/Generator/UrlGeneratorTest.php
+++ b/src/Symfony/Component/Routing/Tests/Generator/UrlGeneratorTest.php
@@ -478,6 +478,38 @@ class UrlGeneratorTest extends TestCase
         $this->assertSame('//EN.FooBar.com/app.php/', $generator->generate('test', array('locale' => 'EN'), UrlGeneratorInterface::NETWORK_PATH));
     }
 
+    public function testDefaultHostIsUsedWhenContextHostIsEmpty()
+    {
+        $routes = $this->getRoutes('test', new Route('/route', array('domain' => 'my.fallback.host'), array('domain' => '.+'), array(), '{domain}', array('http')));
+
+        $generator = $this->getGenerator($routes);
+        $generator->getContext()->setHost('');
+
+        $this->assertSame('http://my.fallback.host/app.php/route', $generator->generate('test', array(), UrlGeneratorInterface::ABSOLUTE_URL));
+    }
+
+    public function testDefaultHostIsUsedWhenContextHostIsEmptyAndSchemeIsNot()
+    {
+        $routes = $this->getRoutes('test', new Route('/route', array('domain' => 'my.fallback.host'), array('domain' => '.+'), array(), '{domain}', array('http', 'https')));
+
+        $generator = $this->getGenerator($routes);
+        $generator->getContext()->setHost('');
+        $generator->getContext()->setScheme('https');
+
+        $this->assertSame('https://my.fallback.host/app.php/route', $generator->generate('test', array(), UrlGeneratorInterface::ABSOLUTE_URL));
+    }
+
+    public function testAbsoluteUrlFallbackToRelativeIfHostIsEmptyAndSchemeIsNot()
+    {
+        $routes = $this->getRoutes('test', new Route('/route', array(), array(), array(), '', array('http', 'https')));
+
+        $generator = $this->getGenerator($routes);
+        $generator->getContext()->setHost('');
+        $generator->getContext()->setScheme('https');
+
+        $this->assertSame('/app.php/route', $generator->generate('test', array(), UrlGeneratorInterface::ABSOLUTE_URL));
+    }
+
     public function testGenerateNetworkPath()
     {
         $routes = $this->getRoutes('test', new Route('/{name}', array(), array(), array(), '{locale}.example.com', array('http')));