Index: cmake/modules/AddSphinxTarget.cmake
===================================================================
--- cmake/modules/AddSphinxTarget.cmake
+++ cmake/modules/AddSphinxTarget.cmake
@@ -53,8 +53,12 @@
                 DESTINATION share/man/man1)
 
       elseif (builder STREQUAL html)
-        install(DIRECTORY "${SPHINX_BUILD_DIR}"
-                DESTINATION "share/doc/${project}")
+        string(TOUPPER "${project}" project_upper)
+        set(${project_upper}_INSTALL_HTML "share/doc/${project}/html"
+            CACHE STRING "HTML documentation install directory for ${project}")
+
+        install(DIRECTORY "${SPHINX_BUILD_DIR}/."
+                DESTINATION "${${project_upper}_INSTALL_HTML}")
       else()
         message(WARNING Installation of ${builder} not supported)
       endif()