diff --git a/Framework/Muon/src/CalMuonDetectorPhases.cpp b/Framework/Muon/src/CalMuonDetectorPhases.cpp
index 7e0b14d20e7946ddd790a601dd86477fb389b778..b68c2ab4374280abba78a8256a9763283aa00853 100644
--- a/Framework/Muon/src/CalMuonDetectorPhases.cpp
+++ b/Framework/Muon/src/CalMuonDetectorPhases.cpp
@@ -398,7 +398,7 @@ void CalMuonDetectorPhases::getGroupingFromInstrument(
   const auto instrument = ws->getInstrument();
   auto loader = Kernel::make_unique<API::GroupingLoader>(instrument);
 
-  if (instrument->getName() == "MUSR") {
+  if (instrument->getName() == "MUSR" || instrument->getName() == "CHRONUS") {
     // Two possibilities for grouping - use workspace log
     auto fieldDir = ws->run().getLogData("main_field_direction");
     if (fieldDir) {
diff --git a/docs/source/release/v4.0.0/muon.rst b/docs/source/release/v4.0.0/muon.rst
index 9b89d0425ecb825731a241c57d55da28699e3c91..84dfb6a93046c94faab621776156a306ceabf327 100644
--- a/docs/source/release/v4.0.0/muon.rst
+++ b/docs/source/release/v4.0.0/muon.rst
@@ -30,6 +30,7 @@ Improvements
 - ALC interface now sorts the data into ascending order.
 - Muon Analysis now includes number of event per frame and number of events per frame per detector in the run info box on the home tab.
 - Frequency Domain Analysis now lets the user select the phase table in MaxEnt mode.
+- CHRONUS now has a transverse and longitudanal default grouping table, the main field direction is read from the file to determine which to use.
 
 Bugfixes
 ########