diff --git a/README.md b/README.md
index 84b16d8..0cdd69e 100644
--- a/README.md
+++ b/README.md
@@ -47,8 +47,8 @@ directory of APE (where `ape.exe` is located). Then type `ape.exe` in the case o
     -ulextext "TEXT"    The user lexicon (taken from a string).
     -ulexfile FILENAME  The user lexicon (taken from a file or URL).
     -solo OUTPUT        Output just one output component. OUTPUT has to be one of {paraphrase,
-                        paraphrase1,paraphrase2,owlfss,owlfsspp,owlrdf,owlxml,fol,pnf,tptp,tokens,
-                        syntax,syntaxpp,syntaxd,syntaxdpp,drs,drsxml,drspp,drshtml}.
+                        paraphrase1,paraphrase2,owlfss,owlfsspp,owlrdf,owlxml,ruleml,fol,pnf,tptp,
+                        tokens,syntax,syntaxpp,syntaxd,syntaxdpp,drs,drsxml,drspp,drshtml}.
     -cdrs               Output the DRS as a Prolog term.
     -cdrsxml            Output the DRS in XML.
     -cdrspp             Output the DRS in pretty-printed form in plain text.
@@ -69,6 +69,7 @@ directory of APE (where `ape.exe` is located). Then type `ape.exe` in the case o
                         printed).
     -cowlxml            Output OWL/SWRL in the XML representation.
     -cowlrdf            Output OWL/SWRL in the RDF/XML representation. DEPRECATED
+    -cruleml            Output RuleML representation of the DRS.
     -cfol               Output standard first-order logic representations (default form) of the DRS
                         as a Prolog term.
     -cpnf               Output standard first-order logic representations (prenex normal form) of
diff --git a/ape.pl b/ape.pl
index 1ca4dd4..e0bede1 100644
--- a/ape.pl
+++ b/ape.pl
@@ -75,7 +75,7 @@
 argument('-file', 'FILENAME', 'The name or URL of the input file containing the ACE text.').
 argument('-ulextext', '"TEXT"', 'The user lexicon (taken from a string).').
 argument('-ulexfile', 'FILENAME', 'The user lexicon (taken from a file or URL).').
-argument('-solo', 'OUTPUT', 'Output just one output component. OUTPUT has to be one of {paraphrase,paraphrase1,paraphrase2,owlfss,owlfsspp,owlrdf,owlxml,fol,pnf,tptp,tokens,syntax,syntaxpp,syntaxd,syntaxdpp,drs,drsxml,drspp,drshtml}.').
+argument('-solo', 'OUTPUT', 'Output just one output component. OUTPUT has to be one of {paraphrase,paraphrase1,paraphrase2,owlfss,owlfsspp,owlrdf,owlxml,ruleml,fol,pnf,tptp,tokens,syntax,syntaxpp,syntaxd,syntaxdpp,drs,drsxml,drspp,drshtml}.').
 argument('-cinput', '', hidden).
 argument('-cdrs', '', 'Output the DRS as a Prolog term.').
 argument('-cdrsxml', '', 'Output the DRS in XML.').
@@ -94,6 +94,7 @@
 argument('-cowlfsspp', '', 'Output OWL/SWRL in the Functional-Style Syntax representation (pretty-printed).').
 argument('-cowlxml', '', 'Output OWL/SWRL in the XML representation.').
 argument('-cowlrdf', '', 'Output OWL/SWRL in the RDF/XML representation. DEPRECATED').
+argument('-cruleml', '', 'Output RuleML representation of the DRS.').
 argument('-cfol', '', 'Output standard first-order logic representations (default form) of the DRS as a Prolog term.').
 argument('-cpnf', '', 'Output standard first-order logic representations (prenex normal form) of the DRS as a Prolog term.').
 argument('-ctptp', '', 'Output TPTP representation of the DRS.').