diff --git a/include/boost/regex/v4/match_results.hpp b/include/boost/regex/v4/match_results.hpp
index 3139a857..fdbc3337 100644
--- a/include/boost/regex/v4/match_results.hpp
+++ b/include/boost/regex/v4/match_results.hpp
@@ -73,7 +73,7 @@ public:
 
    // size:
    size_type size() const
-   { return m_subs.size() - 2; }
+   { return (m_subs.size() >= 2) ? m_subs.size() - 2 : 0; }
    size_type max_size() const
    { return m_subs.max_size(); }
    bool empty() const
@@ -134,7 +134,7 @@ public:
    }
    const_iterator begin() const
    {
-      return (m_subs.size() > 2) ? (m_subs.begin() + 2) : m_subs.end();
+      return (m_subs.size() >= 2) ? (m_subs.begin() + 2) : m_subs.end();
    }
    const_iterator end() const
    {
@@ -218,7 +218,7 @@ public:
       size_type len = m_subs.size();
       if(len > n + 2)
       {
-         m_subs.erase(m_subs.begin()+n+2);
+         m_subs.erase(m_subs.begin()+n+2, m_subs.end());
          std::fill(m_subs.begin(), m_subs.end(), v);
       }
       else