diff --git a/src/math/lp/stacked_vector.h b/src/math/lp/stacked_vector.h
index c38433016..61131955a 100644
--- a/src/math/lp/stacked_vector.h
+++ b/src/math/lp/stacked_vector.h
@@ -135,12 +135,6 @@ public:
     void resize(vector<T> & v, unsigned new_size) {
         v.resize(new_size);
     }
-
-    void pop_back() {
-        unsigned last = m_vector.size() - 1;
-        m_changes.push_back(std::make_pair(last, m_vector[last]));
-        m_vector.pop_back();
-    }
     
     void pop(unsigned k) {
         lp_assert(m_stack_of_vector_sizes.size() >= k);