diff --git a/src/buffer_manager.cc b/src/buffer_manager.cc
index 27187080..c3211f7c 100644
--- a/src/buffer_manager.cc
+++ b/src/buffer_manager.cc
@@ -36,5 +36,17 @@ Buffer* BufferManager::get_buffer(const std::string& name)
     return m_buffers[name].get();
 }
 
+CandidateList BufferManager::complete_buffername(const std::string& prefix,
+                                                 size_t cursor_pos)
+{
+    std::string real_prefix = prefix.substr(0, cursor_pos);
+    CandidateList result;
+    for (auto& buffer : m_buffers)
+    {
+        if (buffer.first.substr(0, real_prefix.length()) == real_prefix)
+            result.push_back(buffer.first);
+    }
+    return result;
+}
 
 }
diff --git a/src/buffer_manager.hh b/src/buffer_manager.hh
index 126b41a3..ee3473cd 100644
--- a/src/buffer_manager.hh
+++ b/src/buffer_manager.hh
@@ -2,6 +2,7 @@
 #define buffer_manager_hh_INCLUDED
 
 #include "buffer.hh"
+#include "completion.hh"
 #include "utils.hh"
 
 #include <unordered_map>
@@ -25,14 +26,17 @@ public:
         Buffer* operator->() const { return parent_type::operator*().second.get(); }
     };
 
-    iterator begin() const { return iterator(m_buffers.begin()); }
-    iterator end() const { return iterator(m_buffers.end()); }
-
     void register_buffer(Buffer* buffer);
     void delete_buffer(Buffer* buffer);
 
+    iterator begin() const { return iterator(m_buffers.begin()); }
+    iterator end() const { return iterator(m_buffers.end()); }
+
     Buffer* get_buffer(const std::string& name);
 
+    CandidateList complete_buffername(const std::string& prefix,
+                                      size_t cursor_pos = std::string::npos);
+
 private:
     BufferMap m_buffers;
 };
diff --git a/src/completion.cc b/src/completion.cc
index 7e570def..936babaa 100644
--- a/src/completion.cc
+++ b/src/completion.cc
@@ -34,18 +34,4 @@ CandidateList complete_filename(const std::string& prefix,
     return result;
 }
 
-CandidateList complete_buffername(const std::string& prefix,
-                                size_t cursor_pos)
-{
-    std::string real_prefix = prefix.substr(0, cursor_pos);
-    CandidateList result;
-    for (auto& buffer : BufferManager::instance())
-    {
-        if (buffer.name().substr(0, real_prefix.length()) == real_prefix)
-            result.push_back(buffer.name());
-    }
-    return result;
-}
-
-
 }
diff --git a/src/completion.hh b/src/completion.hh
index ca325155..af60ed1b 100644
--- a/src/completion.hh
+++ b/src/completion.hh
@@ -26,12 +26,8 @@ struct Completions
 CandidateList complete_filename(const std::string& prefix,
                                 size_t cursor_pos = std::string::npos);
 
-CandidateList complete_buffername(const std::string& prefix,
-                                  size_t cursor_pos = std::string::npos);
-
 typedef std::function<Completions (const std::string&, size_t)> Completer;
 
-
 inline Completions complete_nothing(const std::string&, size_t cursor_pos)
 {
     return Completions(cursor_pos, cursor_pos);
diff --git a/src/main.cc b/src/main.cc
index 4646d04e..cc802111 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -615,7 +615,9 @@ int main(int argc, char* argv[])
     command_manager.register_command(std::vector<std::string>{ "w", "write" }, write_buffer,
                                      PerArgumentCommandCompleter{ complete_filename });
     command_manager.register_command(std::vector<std::string>{ "b", "buffer" }, show_buffer,
-                                     PerArgumentCommandCompleter { complete_buffername });
+                                     PerArgumentCommandCompleter {
+                                         std::bind(&BufferManager::complete_buffername, &buffer_manager, _1, _2)
+                                      });
     command_manager.register_command(std::vector<std::string>{ "af", "addfilter" }, add_filter);
     command_manager.register_command(std::vector<std::string>{ "rf", "rmfilter" }, rm_filter);