diff --git a/Doxyfile.gsm.in b/Doxyfile.gsm.in
index 1dae2b502..feaef0e88 100644
--- a/Doxyfile.gsm.in
+++ b/Doxyfile.gsm.in
@@ -610,7 +610,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories
 # with spaces.
 
-INPUT                  = @srcdir@/include/osmocom/gsm @srcdir@/include/osmocom/gsm/protocol @srcdir@/src/gsm
+INPUT                  = @srcdir@/include/osmocom/gsm @srcdir@/src/gsm
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is