diff --git a/util/perl/OpenSSL/paramnames.pm b/util/perl/OpenSSL/paramnames.pm
index 4d74b69f01..acf4f2e5e5 100644
--- a/util/perl/OpenSSL/paramnames.pm
+++ b/util/perl/OpenSSL/paramnames.pm
@@ -475,6 +475,7 @@ my %params = (
     'SIGNATURE_PARAM_SIGNATURE' =>          "signature",
     'SIGNATURE_PARAM_MESSAGE_ENCODING' =>   "message-encoding",
     'SIGNATURE_PARAM_DETERMINISTIC' =>      "deterministic",
+    'SIGNATURE_PARAM_MU' =>                 "mu", # int
     'SIGNATURE_PARAM_TEST_ENTROPY' =>       "test-entropy",
 
 # Asym cipher parameters