diff --git a/docs/doxygen.conf.in b/docs/doxygen.conf.in
index 4ed7c55..e7a7315 100644
--- a/docs/doxygen.conf.in
+++ b/docs/doxygen.conf.in
@@ -836,7 +836,7 @@
 # Note that the wildcards are matched against the file with absolute path, so to
 # exclude all test directories for example use the pattern */test/*
 
-EXCLUDE_PATTERNS       = */ndn-cxx/detail/* */ndn-cxx/*/detail/*
+EXCLUDE_PATTERNS       = */ndn-cxx/impl/* */ndn-cxx/*/impl/*
 
 # The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
 # (namespaces, classes, functions, etc.) that should be excluded from the