diff --git a/doc/api.rst b/doc/api.rst
index 31b0328d..88ee3e98 100644
--- a/doc/api.rst
+++ b/doc/api.rst
@@ -516,7 +516,7 @@ The format syntax is described in :ref:`chrono-specs`.
 
 .. doxygenfunction:: localtime(std::time_t time)
 
-.. doxygenfunction:: gmtime(std::time_t time)
+.. doxygenfunction:: gmtime(std::time_t time) -> std::tm
 
 .. _std-api: