diff --git a/modules/conop/src/rule_based.cc b/modules/conop/src/rule_based.cc
index 65b89988f2cf35ca1a34be8840e331ccc595a89d..7bbf25f2e3f048f27368ad59d971e20bfb47d340 100644
--- a/modules/conop/src/rule_based.cc
+++ b/modules/conop/src/rule_based.cc
@@ -164,7 +164,6 @@ void RuleBasedProcessor::ProcessUnkAtoms(DiagnosticsPtr diags,
         break;
       case CONOP_FATAL:
         throw DiagError(Diag(DIAG_UNK_ATOM, "unknown atom %0").AddAtom(*i));
-        // FIXME: Implement a ConopError based on Diag...
         break;
       case CONOP_REMOVE_RESIDUE:
         diags->AddDiag(DIAG_UNK_ATOM, "removed residue %0 with unknown atom %1")