diff --git a/src/http_build_url.php b/src/http_build_url.php
index 0dfdbba..14d8e49 100644
--- a/src/http_build_url.php
+++ b/src/http_build_url.php
@@ -93,7 +93,7 @@ function http_build_url($url, $parts = array(), $flags = HTTP_URL_REPLACE, &$new
 			if (isset($parts['path']) && ($flags & HTTP_URL_JOIN_PATH)) {
 				if (isset($url['path']) && substr($parts['path'], 0, 1) !== '/') {
 					// Workaround for trailing slashes
-					$url['path'] .= 'a';
+					$url['path'] .= "\0";
 					$url['path'] = rtrim(
 							str_replace(basename($url['path']), '', $url['path']),
 							'/'
diff --git a/tests/HttpBuildUrlTest.php b/tests/HttpBuildUrlTest.php
index 40a3f15..c32f129 100644
--- a/tests/HttpBuildUrlTest.php
+++ b/tests/HttpBuildUrlTest.php
@@ -170,7 +170,19 @@ public function testJoinPathTwo()
 		$this->assertSame($expected, $actual);
 	}
 
-	/**
+    public function testJoinPathThree()
+    {
+        $expected = "http://site.testing.com/apreview/testing/a/09-20a13/pa0a4/image/15.jpg";
+        $actual = http_build_url(
+            "http://site.testing.com/apreview/testing/a/09-20a13/pa0a4/?code=asdfghjkl",
+            array('path' => 'image/15.jpg'),
+            HTTP_URL_JOIN_PATH | HTTP_URL_STRIP_FRAGMENT | HTTP_URL_STRIP_QUERY
+        );
+
+        $this->assertSame($expected, $actual);
+    }
+
+    /**
 	 * @dataProvider bitmaskProvider
 	 */
 	public function testBitmasks($constant, $expected)