diff --git a/doc/testssl.1 b/doc/testssl.1
index 2f4fea5..33d6404 100644
--- a/doc/testssl.1
+++ b/doc/testssl.1
@@ -349,7 +349,10 @@ Security headers (X\-Frame\-Options, X\-XSS\-Protection, Expect\-CT,\.\.\. , CSP
 \fB\-T, \-\-ticketbleed\fR Checks for Ticketbleed memory leakage in BigIP loadbalancers\.
 .
 .P
-\fB\-BB, \-\-robot\fR Checks for vulnerability to ROBOT / (\fIReturn Of Bleichenbacher\'s Oracle Threat\fR) attack\.
+\fB\-\-BB, \-\-robot\fR Checks for vulnerability to ROBOT / (\fIReturn Of Bleichenbacher\'s Oracle Threat\fR) attack\.
+.
+.P
+\fB\-\-SI, \-\-starttls\-injection\fR Checks for STARTTLS injection vulnerabilities (SMTP, IMAP, POP3 only)\. \fIsocat\fR and OpenSSL >=1.1.0 is needed\.
 .
 .P
 \fB\-R, \-\-renegotiation\fR Tests renegotiation vulnerabilities\. Currently there\'s a check for \fISecure Renegotiation\fR and for \fISecure Client\-Initiated Renegotiation\fR\. Please be aware that vulnerable servers to the latter can likely be DoSed very easily (HTTP)\. A check for \fIInsecure Client\-Initiated Renegotiation\fR is not yet implemented\.
diff --git a/doc/testssl.1.html b/doc/testssl.1.html
index 2d66208..52f929e 100644
--- a/doc/testssl.1.html
+++ b/doc/testssl.1.html
@@ -315,7 +315,9 @@ Also for multiple server certificates are being checked for as well as for the c
 
 <p><code>-T, --ticketbleed</code>             Checks for Ticketbleed memory leakage in BigIP loadbalancers.</p>
 
-<p><code>-BB, --robot</code>          Checks for vulnerability to ROBOT / (<em>Return Of Bleichenbacher's Oracle Threat</em>) attack.</p>
+<p><code>--BB, --robot</code>          Checks for vulnerability to ROBOT / (<em>Return Of Bleichenbacher's Oracle Threat</em>) attack.</p>
+
+<p><code>--SI, --starttls-injection</code>          Checks for STARTTLS injection vulnerabilities (SMTP, IMAP, POP3 only). <code>socat</code> and OpenSSL &ge;1.1.0 is needed.</p>
 
 <p><code>-R, --renegotiation</code>           Tests renegotiation vulnerabilities. Currently there's a check for <em>Secure Renegotiation</em> and for <em>Secure Client-Initiated Renegotiation</em>. Please be aware that vulnerable servers to the latter can likely be DoSed very easily (HTTP). A check for <em>Insecure Client-Initiated Renegotiation</em> is not yet implemented.</p>
 
diff --git a/doc/testssl.1.md b/doc/testssl.1.md
index 42f8c7e..cdca42b 100644
--- a/doc/testssl.1.md
+++ b/doc/testssl.1.md
@@ -229,7 +229,9 @@ Also for multiple server certificates are being checked for as well as for the c
 
 `-T, --ticketbleed`             Checks for Ticketbleed memory leakage in BigIP loadbalancers.
 
-`-BB, --robot`          Checks for vulnerability to ROBOT / (*Return Of Bleichenbacher's Oracle Threat*) attack.
+`--BB, --robot`          Checks for vulnerability to ROBOT / (*Return Of Bleichenbacher's Oracle Threat*) attack.
+
+`--SI, --starttls-injection`          Checks for STARTTLS injection vulnerabilities (SMTP, IMAP, POP3 only). `socat` and OpenSSL >=1.1.0 is needed.
 
 `-R, --renegotiation`           Tests renegotiation vulnerabilities. Currently there's a check for *Secure Renegotiation* and for *Secure Client-Initiated Renegotiation*. Please be aware that vulnerable servers to the latter can likely be DoSed very easily (HTTP). A check for *Insecure Client-Initiated Renegotiation* is not yet implemented.