diff --git a/src/controllerclientimpl.cpp b/src/controllerclientimpl.cpp
index ebff0fd6..5fbd905a 100644
--- a/src/controllerclientimpl.cpp
+++ b/src/controllerclientimpl.cpp
@@ -600,6 +600,14 @@ int ControllerClientImpl::_CallGet(const std::string& desturi, std::string& outp
     return http_code;
 }
 
+int ControllerClientImpl::_DuplicateStreamCallback(char *data, size_t size, size_t nmemb, void **writerDataStringStreamAndOStream)
+{
+    if(((std::stringstream*)writerDataStringStreamAndOStream[0])->tellp() < 0x1000) {
+        ControllerClientImpl::_WriteStringStreamCallback(data, size, nmemb, (std::stringstream*)writerDataStringStreamAndOStream[0]);
+    }
+    return ControllerClientImpl::_WriteOStreamCallback(data, size, nmemb, (std::ostream*)writerDataStringStreamAndOStream[1]);
+}
+
 int ControllerClientImpl::CallGet(const std::string& relativeuri, std::ostream& outputStream, int expectedhttpcode, double timeout)
 {
     boost::mutex::scoped_lock lock(_mutex);
@@ -614,15 +622,25 @@ int ControllerClientImpl::_CallGet(const std::string& desturi, std::ostream& out
     CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_TIMEOUT_MS, 0L, (long)(timeout * 1000L));
     CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_HTTPHEADER, NULL, _httpheadersjson);
     CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_URL, NULL, desturi.c_str());
-    CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_WRITEFUNCTION, NULL, _WriteOStreamCallback);
-    CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_WRITEDATA, NULL, &outputStream);
+    _buffer.clear();
+    _buffer.str("");
+    CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_WRITEFUNCTION, NULL, _DuplicateStreamCallback);
+    void *writerData[]={&_buffer,&outputStream};
+    CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_WRITEDATA, NULL, writerData);
     CURL_OPTION_SAVE_SETTER(_curl, CURLOPT_HTTPGET, 0L, 1L);
     CURL_PERFORM(_curl);
     long http_code = 0;
     CURL_INFO_GETTER(_curl, CURLINFO_RESPONSE_CODE, &http_code);
+    std::string outputdata = _buffer.str();
     if( expectedhttpcode != 0 && http_code != expectedhttpcode ) {
-        // outputStream is not always seekable; ignore any error message.
-        throw MUJIN_EXCEPTION_FORMAT("HTTP GET to '%s' returned HTTP status %s (outputStream might have information)", desturi%http_code, MEC_HTTPServer);
+        if( outputdata.size() > 0 ) {
+            rapidjson::Document d;
+            ParseJson(d, _buffer.str());
+            std::string error_message = GetJsonValueByKey<std::string>(d, "error_message");
+            std::string traceback = GetJsonValueByKey<std::string>(d, "traceback");
+            throw MUJIN_EXCEPTION_FORMAT("HTTP GET to '%s' returned HTTP status %s: %s", desturi%http_code%error_message, MEC_HTTPServer);
+        }
+        throw MUJIN_EXCEPTION_FORMAT("HTTP GET to '%s' returned HTTP status %s", desturi%http_code, MEC_HTTPServer);
     }
     return http_code;
 }
diff --git a/src/controllerclientimpl.h b/src/controllerclientimpl.h
index 393055d3..f08672c3 100644
--- a/src/controllerclientimpl.h
+++ b/src/controllerclientimpl.h
@@ -181,6 +181,7 @@ class ControllerClientImpl : public ControllerClient, public boost::enable_share
     static int _WriteVectorCallback(char *data, size_t size, size_t nmemb, std::vector<unsigned char> *writerData);
     static int _WriteOStreamCallback(char *data, size_t size, size_t nmemb, std::ostream *writerData);
     static int _ReadIStreamCallback(char *data, size_t size, size_t nmemb, std::istream *writerData);
+    static int _DuplicateStreamCallback(char *data, size_t size, size_t nmemb, void **writerDataStringStreamAndOStream);
 
     /// \brief sets up http header for doing http operation with json data
     void _SetupHTTPHeadersJSON();