diff --git a/Utilities/Sphinx/CMakeLists.txt b/Utilities/Sphinx/CMakeLists.txt
index 51c83ba6f..4ae4bec21 100644
--- a/Utilities/Sphinx/CMakeLists.txt
+++ b/Utilities/Sphinx/CMakeLists.txt
@@ -75,6 +75,10 @@ if(SPHINX_QTHELP)
   list(APPEND doc_formats qthelp)
 
   set(qthelp_extra_commands
+    # Workaround for assistant prior to
+    # https://codereview.qt-project.org/#change,82250 in Qt 4.
+    COMMAND ${CMAKE_COMMAND} "-DCSS_DIR=${CMAKE_CURRENT_BINARY_DIR}/qthelp/_static"
+      -P "${CMAKE_CURRENT_SOURCE_DIR}/apply_qthelp_css_workaround.cmake"
     COMMAND qcollectiongenerator ${CMAKE_CURRENT_BINARY_DIR}/qthelp/CMake.qhcp
   )
 endif()
diff --git a/Utilities/Sphinx/apply_qthelp_css_workaround.cmake b/Utilities/Sphinx/apply_qthelp_css_workaround.cmake
new file mode 100644
index 000000000..8b74d12bb
--- /dev/null
+++ b/Utilities/Sphinx/apply_qthelp_css_workaround.cmake
@@ -0,0 +1,15 @@
+
+file(READ "${CSS_DIR}/basic.css" BasicCssContent)
+
+file(READ "${CSS_DIR}/default.css" DefaultCssContent)
+string(REPLACE
+  "@import url(\"basic.css\")" "${BasicCssContent}"
+  DefaultCssContent "${DefaultCssContent}"
+)
+
+file(READ "${CSS_DIR}/cmake.css" CMakeCssContent)
+string(REPLACE
+  "@import url(\"default.css\")" "${DefaultCssContent}"
+  CMakeCssContent "${CMakeCssContent}"
+)
+file(WRITE "${CSS_DIR}/cmake.css" "${CMakeCssContent}")