diff --git a/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jHttpProxy.java b/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jHttpProxy.java
index 55218cc..38fab94 100644
--- a/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jHttpProxy.java
+++ b/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jHttpProxy.java
@@ -130,10 +130,12 @@ public byte[] getResponse(URL url, String request)
                     new ByteArrayOutputStream();
                 final byte[] buf = new byte[1024];
                 int count;
-                while ((count = errorStream.read(buf)) > 0) {
-                    baos.write(buf, 0, count);
+                if (errorStream != null) {
+                    while ((count = errorStream.read(buf)) > 0) {
+                        baos.write(buf, 0, count);
+                    }
+                    errorStream.close();
                 }
-                errorStream.close();
                 baos.close();
             } catch (IOException ex) {
                 // Well, we tried. No point notifying the user here.