--- lib/IO/Socket/SSL.pm
+++ lib/IO/Socket/SSL.pm
@@ -83,7 +83,7 @@ my $algo2digest = do {
 # global defaults
 my %DEFAULT_SSL_ARGS = (
     SSL_check_crl => 0,
-    SSL_version => 'SSLv23:!SSLv2',
+    SSL_version => '',
     SSL_verify_callback => undef,
     SSL_verifycn_scheme => undef,  # fallback cn verification
     SSL_verifycn_publicsuffix => undef,  # fallback default list verification
@@ -2043,7 +2043,7 @@ WARN
 
     my $ssl_op = Net::SSLeay::OP_ALL();
 
-    my $ver;
+    my $ver = '';
     for (split(/\s*:\s*/,$arg_hash->{SSL_version})) {
 	m{^(!?)(?:(SSL(?:v2|v3|v23|v2/3))|(TLSv1(?:_?[12])?))$}i
 	or croak("invalid SSL_version specified");
--- lib/IO/Socket/SSL.pod
+++ lib/IO/Socket/SSL.pod
@@ -910,7 +910,8 @@ recent versions of Net::SSLeay and opens
 
 You can limit to set of supported protocols by adding !version separated by ':'.
 
-The default SSL_version is 'SSLv23:!SSLv2' which means, that SSLv2, SSLv3 and
+The default SSL_version is defined by underlying cryptographic library.
+For example, 'SSLv23:!SSLv2' means that SSLv2, SSLv3 and TLSv1
 TLSv1 are supported for initial protocol handshakes, but SSLv2 will not be
 accepted, leaving only SSLv3 and TLSv1. You can also use !TLSv1_1 and !TLSv1_2
 to disable TLS versions 1.1 and 1.2 while allowing TLS version 1.0.