diff --git a/doc/Doxyfile.cmake b/doc/Doxyfile.cmake
index f2ba37ad..f60c53f6 100644
--- a/doc/Doxyfile.cmake
+++ b/doc/Doxyfile.cmake
@@ -122,7 +122,7 @@ HTML_OUTPUT = html
 HTML_FILE_EXTENSION = .html
 HTML_HEADER = 
 HTML_FOOTER = 
-HTML_EXTRA_STYLESHEET = @CMAKE_SOURCE_DIR@/doc/doxy_formula.css
+HTML_EXTRA_STYLESHEET = @CMAKE_SOURCE_DIR@/doc/doxygen/custom.css
 HTML_ALIGN_MEMBERS = YES
 HTML_EXTRA_FILES = @CMAKE_SOURCE_DIR@/doc/fluidsettings.xml @CMAKE_SOURCE_DIR@/doc/fluidsettings.xsl @CMAKE_SOURCE_DIR@/doc/FluidMixer.pdf @CMAKE_SOURCE_DIR@/doc/FluidMixer.jpg
 GENERATE_HTMLHELP = NO
diff --git a/doc/doxy_formula.css b/doc/doxygen/custom.css
similarity index 100%
rename from doc/doxy_formula.css
rename to doc/doxygen/custom.css