diff --git a/src/core/GapBuffer.h b/src/core/GapBuffer.h
index c544763..0931e9e 100644
--- a/src/core/GapBuffer.h
+++ b/src/core/GapBuffer.h
@@ -41,8 +41,8 @@ public:
                 return 0xFFFFFFFFu;
             }
         }
-        GapBuffer * gap_buffer() { return m_gap_buffer; }
-        bool operator<(const Iterator & other)
+        GapBuffer * gap_buffer() const { return m_gap_buffer; }
+        bool operator<(const Iterator & other) const
         {
             return m_offset < other.m_offset;
         }
@@ -69,11 +69,12 @@ public:
         bool go_right(bool allow_eol);
         bool go_up(size_t target_column);
         bool go_down(size_t target_column);
-        bool operator<(const Cursor & other)
+        bool operator<(const Cursor & other) const
         {
             return m_iterator < other.m_iterator;
         }
-        uint32_t operator*() { return *m_iterator; }
+        uint32_t operator*() const { return *m_iterator; }
+        uint8_t * address() const { return m_iterator.address(); }
 
     protected:
         Iterator m_iterator;