diff --git a/docs/doxygen.conf.in b/docs/doxygen.conf.in
index 8e31136..d70ac1c 100644
--- a/docs/doxygen.conf.in
+++ b/docs/doxygen.conf.in
@@ -230,12 +230,6 @@
 
 ALIASES                =
 
-# This tag can be used to specify a number of word-keyword mappings (TCL only).
-# A mapping has the form "name=value". For example adding "class=itcl::class"
-# will allow you to use the command class in the itcl::class meaning.
-
-TCL_SUBST              =
-
 # Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
 # only. Doxygen will then generate output that is more tailored for C. For
 # instance, some of the names that are used will be different. The list of all
@@ -2161,7 +2155,7 @@
 # set to NO
 # The default value is: YES.
 
-HAVE_DOT               = YES
+HAVE_DOT               = @HAVE_DOT@
 
 # The DOT_NUM_THREADS specifies the number of dot invocations doxygen is allowed
 # to run in parallel. When set to 0 doxygen will base this on the number of