1 files changed, 5 insertions, 1 deletions
diff --git a/src/theory/datatypes/theory_datatypes.cpp b/src/theory/datatypes/theory_datatypes.cpp
index 9d3b5a143..45787ee04 100644
--- a/src/theory/datatypes/theory_datatypes.cpp
+++ b/src/theory/datatypes/theory_datatypes.cpp
@@ -1562,11 +1562,15 @@ void TheoryDatatypes::instantiate( EqcInfo* eqc, Node n ){
   // may contribute to conflicts due to cardinality (good examples of this are
   // regress0/datatypes/dt-param-card4-bool-sat.smt2 and
   // regress0/datatypes/list-bool.smt2).
-  bool forceLemma = true;
+  bool forceLemma;
   if (options::dtPoliteOptimize())
   {
     forceLemma = dt[index].hasFiniteExternalArgType(ttn);
   }
+  else
+  {
+    forceLemma = dt.involvesExternalType();
+  }
   Trace("datatypes-infer-debug") << "DtInstantiate : " << eqc << " " << eq
                                  << " forceLemma = " << forceLemma << std::endl;
   d_im.addPendingInference(eq, InferenceId::DATATYPES_INST, exp, forceLemma);