diff --git a/src/smt/asserted_formulas.cpp b/src/smt/asserted_formulas.cpp
index d44548f0b..b1e89f72e 100644
--- a/src/smt/asserted_formulas.cpp
+++ b/src/smt/asserted_formulas.cpp
@@ -439,7 +439,6 @@ void asserted_formulas::commit(unsigned new_qhead) {
         justified_expr const& j = m_formulas[i];
         update_substitution(j.get_fml(), j.get_proof());
     }
-    (void)new_sub;
     m_qhead = new_qhead;
 }