diff --git a/gtsam/inference/IndexFactor.cpp b/gtsam/inference/IndexFactor.cpp
index 5041e87dc..22e1a4619 100644
--- a/gtsam/inference/IndexFactor.cpp
+++ b/gtsam/inference/IndexFactor.cpp
@@ -30,11 +30,13 @@ template class Factor<Index>;
 
 /* ************************************************************************* */
 void IndexFactor::assertInvariants() const {
-  Base::assertInvariants();
+	Base::assertInvariants();
 #ifndef NDEBUG
+#ifndef GTSAM_NO_ENFORCE_ORDERING
   std::set<Index> uniqueSorted(keys_.begin(), keys_.end());
   assert(uniqueSorted.size() == keys_.size() && std::equal(uniqueSorted.begin(), uniqueSorted.end(), keys_.begin()));
 #endif
+#endif
 }
 
 /* ************************************************************************* */