diff --git a/elem_out.cpp b/elem_out.cpp
index 57c0f5c4..e7bb22cc 100644
--- a/elem_out.cpp
+++ b/elem_out.cpp
@@ -4170,6 +4170,7 @@ static void improve_mpc_colors( const int n_obs, const OBSERVE FAR *obs,
          assert( color >=0 && color < max_n_colors);
          }
       n_iterations++;
+      assert( n_iterations < 10);
       }
 }