diff --git a/src/buffer.hh b/src/buffer.hh
index 03b96b34..8f3121e5 100644
--- a/src/buffer.hh
+++ b/src/buffer.hh
@@ -31,7 +31,7 @@ public:
     typedef size_t difference_type;
     typedef const value_type* pointer;
     typedef const value_type& reference;
-    typedef std::bidirectional_iterator_tag iterator_category;
+    typedef std::random_access_iterator_tag iterator_category;
 
     BufferIterator() : m_buffer(nullptr) {}
     BufferIterator(const Buffer& buffer, BufferCoord coord);
@@ -44,6 +44,7 @@ public:
     bool operator>= (const BufferIterator& iterator) const;
 
     char   operator* () const;
+    char   operator[](size_t n) const;
     size_t operator- (const BufferIterator& iterator) const;
 
     BufferIterator operator+ (ByteCount size) const;
diff --git a/src/buffer_iterator.inl.hh b/src/buffer_iterator.inl.hh
index fb3a8a1d..1d3953ba 100644
--- a/src/buffer_iterator.inl.hh
+++ b/src/buffer_iterator.inl.hh
@@ -62,6 +62,11 @@ inline char BufferIterator::operator*() const
     return m_buffer->at(m_coord);
 }
 
+inline char BufferIterator::operator[](size_t n) const
+{
+    return m_buffer->at(m_buffer->advance(m_coord, n));
+}
+
 inline size_t BufferIterator::operator-(const BufferIterator& iterator) const
 {
     kak_assert(m_buffer == iterator.m_buffer);