--- old/src/java.httpclient/share/classes/java/net/http/HttpRequestBuilderImpl.java	2016-04-29 11:47:25.955376099 +0100
+++ new/src/java.httpclient/share/classes/java/net/http/HttpRequestBuilderImpl.java	2016-04-29 11:47:25.783376094 +0100
@@ -39,10 +39,11 @@
     private HttpClient.Version version;
     private final HttpClientImpl client;
     private ProxySelector proxy;
-    private long timeval = 0;
+    private long timeval;
 
     public HttpRequestBuilderImpl(HttpClientImpl client, URI uri) {
         this.client = client;
+        checkURI(uri);
         this.uri = uri;
         this.version = client.version();
         this.userHeaders = new HttpHeadersImpl();
@@ -58,10 +59,17 @@
     @Override
     public HttpRequestBuilderImpl uri(URI uri) {
         Objects.requireNonNull(uri);
+        checkURI(uri);
         this.uri = uri;
         return this;
     }
 
+    private static void checkURI(URI uri) {
+        String scheme = uri.getScheme().toLowerCase();
+        if (!scheme.equals("https") && !scheme.equals("http"))
+            throw new IllegalArgumentException("invalid URI scheme");
+    }
+
     @Override
     public HttpRequestBuilderImpl followRedirects(HttpClient.Redirect follow) {
         Objects.requireNonNull(follow);