diff --git a/Grid/qcd/action/gauge/GaugeImplTypes.h b/Grid/qcd/action/gauge/GaugeImplTypes.h
index a9af1fae..8bbcde10 100644
--- a/Grid/qcd/action/gauge/GaugeImplTypes.h
+++ b/Grid/qcd/action/gauge/GaugeImplTypes.h
@@ -176,6 +176,8 @@ public:
     Group::ColdConfiguration(pRNG, U);
   }
 
+  static const int num_colours = Group::Dimension;
+
 };