diff --git a/doc/doxygen/Doxyfile b/doc/doxygen/Doxyfile
index 3865729fe56a1204854831fe7b95b1e46a06f17d..9edf977f257aceccf1f618872200b9f4a5a0f8dc 100644
--- a/doc/doxygen/Doxyfile
+++ b/doc/doxygen/Doxyfile
@@ -664,10 +664,10 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories
 # with spaces.
 
-INPUT                  = doxygen.main \
-                         doxygen.source \
-                         doxygen.intern \
-                         doxygen.extern \
+INPUT                  = doxygen.main.h \
+                         doxygen.source.h \
+                         doxygen.intern.h \
+                         doxygen.extern.h \
                          ../../source \
                          ../../intern \
                          ../../extern/bullet2
diff --git a/doc/doxygen/doxygen.extern b/doc/doxygen/doxygen.extern.h
similarity index 100%
rename from doc/doxygen/doxygen.extern
rename to doc/doxygen/doxygen.extern.h
diff --git a/doc/doxygen/doxygen.intern b/doc/doxygen/doxygen.intern.h
similarity index 100%
rename from doc/doxygen/doxygen.intern
rename to doc/doxygen/doxygen.intern.h
diff --git a/doc/doxygen/doxygen.main b/doc/doxygen/doxygen.main.h
similarity index 100%
rename from doc/doxygen/doxygen.main
rename to doc/doxygen/doxygen.main.h
diff --git a/doc/doxygen/doxygen.source b/doc/doxygen/doxygen.source.h
similarity index 100%
rename from doc/doxygen/doxygen.source
rename to doc/doxygen/doxygen.source.h