Index: src/main/java/org/openrdf/repository/base/RepositoryConnectionBase.java
===================================================================
--- src/main/java/org/openrdf/repository/base/RepositoryConnectionBase.java	(revision 10347)
+++ src/main/java/org/openrdf/repository/base/RepositoryConnectionBase.java	(working copy)
@@ -13,6 +13,7 @@
 import java.io.InputStream;
 import java.io.Reader;
 import java.net.URL;
+import java.net.URLConnection;
 import java.util.zip.GZIPInputStream;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
@@ -217,7 +218,10 @@
 			dataFormat = Rio.getParserFormatForFileName(url.getPath());
 		}
 
-		InputStream in = url.openStream();
+		URLConnection connection = url.openConnection();
+		connection.setRequestProperty("Accept", dataFormat.getDefaultMIMEType());
+		
+		InputStream in = connection.getInputStream();
 		try {
 			add(in, baseURI, dataFormat, contexts);
 		}