diff --git a/src/commands.cc b/src/commands.cc
index 27531aec..b63353c3 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -826,7 +826,7 @@ const CommandDesc rename_buffer_cmd = {
     [](const ParametersParser& parser, Context& context, const ShellContext&)
     {
         if (not context.buffer().set_name(parser[0]))
-            throw runtime_error(format("unable to change buffer name to '{}'", parser[0]));
+            throw runtime_error(format("unable to change buffer name to '{}': a buffer with this name already exists", parser[0]));
     }
 };