diff --git a/grc/digitalhf_doppler_correction_cc.xml b/grc/digitalhf_doppler_correction_cc.xml
index 7029216..83c0f74 100644
--- a/grc/digitalhf_doppler_correction_cc.xml
+++ b/grc/digitalhf_doppler_correction_cc.xml
@@ -4,35 +4,23 @@
   <key>digitalhf_doppler_correction_cc</key>
   <category>[digitalhf]</category>
   <import>import digitalhf</import>
-  <make>digitalhf.doppler_correction_cc($length)</make>
-  <!-- Make one 'param' node for every Parameter you want settable from the GUI.
-       Sub-nodes:
-       * name
-       * key (makes the value accessible as $keyname, e.g. in the make node)
-       * type -->
+  <make>digitalhf.doppler_correction_cc($preamble_length, $preamble_length_cc)</make>
   <param>
-    <name>...</name>
-    <key>...</key>
-    <type>...</type>
+    <name>preamble_length</name>
+    <key>preamble_length</key>
+    <type>int</type>
+  </param>
+  <param>
+    <name>preamble_length_cc</name>
+    <key>preamble_length_cc</key>
+    <type>int</type>
   </param>
-
-  <!-- Make one 'sink' node per input. Sub-nodes:
-       * name (an identifier for the GUI)
-       * type
-       * vlen
-       * optional (set to 1 for optional inputs) -->
   <sink>
     <name>in</name>
-    <type><!-- e.g. int, float, complex, byte, short, xxx_vector, ...--></type>
+    <type>complex</type>
   </sink>
-
-  <!-- Make one 'source' node per output. Sub-nodes:
-       * name (an identifier for the GUI)
-       * type
-       * vlen
-       * optional (set to 1 for optional inputs) -->
   <source>
     <name>out</name>
-    <type><!-- e.g. int, float, complex, byte, short, xxx_vector, ...--></type>
+    <type>complex</type>
   </source>
 </block>