diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8a3ea44a36a..97d2eb19ee4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -615,6 +615,7 @@ if(ENABLE_EXAMPLE)
 endif()
 
 if(ENABLE_DOCS)
+  set(DOC_LANG en CACHE STRING "Document language option")
   add_subdirectory(doc)
 endif()
 add_subdirectory(rc)
@@ -716,5 +717,8 @@ cmake_print_variables(TS_PKGSYSGROUP)
 cmake_print_variables(BUILD_MACHINE)
 cmake_print_variables(DEFAULT_STACK_SIZE)
 cmake_print_variables(CMAKE_INSTALL_RPATH)
+if(DEFINED DOC_LANG)
+  cmake_print_variables(DOC_LANG)
+endif(DEFINED DOC_LANG)
 
 print_auto_options_summary()
diff --git a/doc/conf.cmake.in.py b/doc/conf.cmake.in.py
index e5f534bbff4..a5761d7b129 100644
--- a/doc/conf.cmake.in.py
+++ b/doc/conf.cmake.in.py
@@ -110,7 +110,7 @@ def setup(app):
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-#language = None
+language = '@DOC_LANG@'
 locale_dirs = ['locale/']
 gettext_compact = False