diff --git a/Doxyfile.in b/Doxyfile.in
index a1f3f8819e..56d59f8a64 100644
--- a/Doxyfile.in
+++ b/Doxyfile.in
@@ -1990,12 +1990,6 @@ EXTERNAL_GROUPS        = YES
 
 EXTERNAL_PAGES         = YES
 
-# The PERL_PATH should be the absolute path and name of the perl script
-# interpreter (i.e. the result of 'which perl').
-# The default file (with absolute path) is: /usr/bin/perl.
-
-PERL_PATH              = /usr/bin/perl
-
 #---------------------------------------------------------------------------
 # Configuration options related to the dot tool
 #---------------------------------------------------------------------------
@@ -2009,15 +2003,6 @@ PERL_PATH              = /usr/bin/perl
 
 CLASS_DIAGRAMS         = YES
 
-# You can define message sequence charts within doxygen comments using the \msc
-# command. Doxygen will then run the mscgen tool (see:
-# http://www.mcternan.me.uk/mscgen/)) to produce the chart and insert it in the
-# documentation. The MSCGEN_PATH tag allows you to specify the directory where
-# the mscgen tool resides. If left empty the tool is assumed to be found in the
-# default search path.
-
-MSCGEN_PATH            =
-
 # You can include diagrams made with dia in doxygen documentation. Doxygen will
 # then run dia to produce the diagram and insert it in the documentation. The
 # DIA_PATH tag allows you to specify the directory where the dia binary resides.
diff --git a/src/charon-nm/nm/nm_backend.h b/src/charon-nm/nm/nm_backend.h
index cbc14a0919..1ae14627a8 100644
--- a/src/charon-nm/nm/nm_backend.h
+++ b/src/charon-nm/nm/nm_backend.h
@@ -28,8 +28,6 @@
 
 /**
  * Initialize the NetworkManager backend.
- *
- * @return		TRUE, if initialization was successful
  */
 void nm_backend_register();
 
diff --git a/src/libstrongswan/plugins/botan/botan_ec_public_key.h b/src/libstrongswan/plugins/botan/botan_ec_public_key.h
index ddb3d5b046..995b557444 100644
--- a/src/libstrongswan/plugins/botan/botan_ec_public_key.h
+++ b/src/libstrongswan/plugins/botan/botan_ec_public_key.h
@@ -22,6 +22,11 @@
  * THE SOFTWARE.
  */
 
+/**
+ * @defgroup botan_ec_public_key botan_ec_public_key
+ * @{ @ingroup botan_p
+ */
+
 #ifndef BOTAN_EC_PUBLIC_KEY_H_
 #define BOTAN_EC_PUBLIC_KEY_H_
 
diff --git a/src/libstrongswan/plugins/botan/botan_ed_public_key.h b/src/libstrongswan/plugins/botan/botan_ed_public_key.h
index 0f44b1afba..17ca0ea297 100644
--- a/src/libstrongswan/plugins/botan/botan_ed_public_key.h
+++ b/src/libstrongswan/plugins/botan/botan_ed_public_key.h
@@ -21,6 +21,11 @@
  * THE SOFTWARE.
  */
 
+/**
+ * @defgroup botan_ed_public_key botan_ed_public_key
+ * @{ @ingroup botan_p
+ */
+
 #ifndef BOTAN_ED_PUBLIC_KEY_H_
 #define BOTAN_ED_PUBLIC_KEY_H_