--- lib/IO/Socket/SSL.pm
+++ lib/IO/Socket/SSL.pm
@@ -164,7 +164,7 @@ if ( defined &Net::SSLeay::CTX_set_min_p
 # global defaults
 my %DEFAULT_SSL_ARGS = (
     SSL_check_crl => 0,
-    SSL_version => 'SSLv23:!SSLv3:!SSLv2', # consider both SSL3.0 and SSL2.0 as broken
+    SSL_version => '',
     SSL_verify_callback => undef,
     SSL_verifycn_scheme => undef,  # fallback cn verification
     SSL_verifycn_publicsuffix => undef,  # fallback default list verification
@@ -2335,7 +2335,7 @@ sub new {
 
     my $ssl_op = $DEFAULT_SSL_OP;
 
-    my $ver;
+    my $ver = '';
     for (split(/\s*:\s*/,$arg_hash->{SSL_version})) {
 	m{^(!?)(?:(SSL(?:v2|v3|v23|v2/3))|(TLSv1(?:_?[123])?))$}i
 	or croak("invalid SSL_version specified");
--- lib/IO/Socket/SSL.pod
+++ lib/IO/Socket/SSL.pod
@@ -1028,11 +1028,12 @@ All values are case-insensitive.  Instea
 'TLSv1_3' one can also use 'TLSv11', 'TLSv12', and 'TLSv13'.  Support for
 'TLSv1_1', 'TLSv1_2', and 'TLSv1_3' requires recent versions of Net::SSLeay
 and openssl.
+The default SSL_version is defined by the underlying cryptographic library.
 
 Independent from the handshake format you can limit to set of accepted SSL
 versions by adding !version separated by ':'.
 
-The default SSL_version is 'SSLv23:!SSLv3:!SSLv2' which means, that the
+For example, 'SSLv23:!SSLv3:!SSLv2' means that the
 handshake format is compatible to SSL2.0 and higher, but that the successful
 handshake is limited to TLS1.0 and higher, that is no SSL2.0 or SSL3.0 because
 both of these versions have serious security issues and should not be used