diff --git a/src/smt/theory_diff_logic_def.h b/src/smt/theory_diff_logic_def.h
index 2199c46c0..f0692ae57 100644
--- a/src/smt/theory_diff_logic_def.h
+++ b/src/smt/theory_diff_logic_def.h
@@ -814,6 +814,8 @@ theory_var theory_diff_logic<Ext>::mk_var(enode* n) {
 
 template<typename Ext>
 void theory_diff_logic<Ext>::set_sort(expr* n) {
+    if (m_util.is_numeral(n))
+        return;
     if (m_util.is_int(n)) {
         if (m_lia_or_lra == is_lra) {
             throw default_exception("difference logic does not work with mixed sorts");