diff --git a/src/smt/theory_seq.cpp b/src/smt/theory_seq.cpp
index d2c4d93e6..a537f2678 100644
--- a/src/smt/theory_seq.cpp
+++ b/src/smt/theory_seq.cpp
@@ -3125,6 +3125,9 @@ void theory_seq::assign_eh(bool_var v, bool is_true) {
     else if (m_util.is_skolem(e)) {
         
         // no-op
+    }
+    else if (m_util.str.is_is_digit(e)) {
+	
     }
     else {
         TRACE("seq", tout << mk_pp(e, m) << "\n";);