diff --git a/doc/guix.texi b/doc/guix.texi
index 858d5751bf..d9b55b3c1f 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -28551,6 +28551,12 @@ Messaging Services
 Defaults to @samp{'("DIGEST-MD5")}.
 @end deftypevr
 
+@deftypevr {@code{prosody-configuration} parameter} string-list insecure-sasl-mechanisms
+Set of mechanisms that will not be offered on unencrypted connections.
+See @url{https://prosody.im/doc/modules/mod_saslauth}.
+Defaults to @samp{'("PLAIN" "LOGIN")}.
+@end deftypevr
+
 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
 Whether to force all server-to-server connections to be encrypted or not.
 See @url{https://prosody.im/doc/modules/mod_tls}.
@@ -28630,7 +28636,7 @@ Messaging Services
 
 Available @code{virtualhost-configuration} fields are:
 
-all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
+all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{insecure-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
 @deftypevr {@code{virtualhost-configuration} parameter} string domain
 Domain you wish Prosody to serve.
 @end deftypevr
@@ -28652,7 +28658,7 @@ Messaging Services
 
 Available @code{int-component-configuration} fields are:
 
-all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
+all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{insecure-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
 @deftypevr {@code{int-component-configuration} parameter} string hostname
 Hostname of the component.
 @end deftypevr
@@ -28705,7 +28711,7 @@ Messaging Services
 
 Available @code{ext-component-configuration} fields are:
 
-all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
+all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{insecure-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
 Password which the component will use to log in.
 @end deftypevr
diff --git a/gnu/services/messaging.scm b/gnu/services/messaging.scm
index 9702170b3e..a914d0f89e 100644
--- a/gnu/services/messaging.scm
+++ b/gnu/services/messaging.scm
@@ -427,6 +427,12 @@ (define %default-modules-enabled
 @url{https://prosody.im/doc/modules/mod_saslauth}."
      common)
 
+    (insecure-sasl-mechanisms
+     (string-list '("PLAIN" "LOGIN"))
+     "Set of mechanisms that will not be offered on unencrypted connections.
+See @url{https://prosody.im/doc/modules/mod_saslauth}."
+     common)
+
     (s2s-require-encryption?
      (boolean #f)
      "Whether to force all server-to-server connections to be encrypted or not.
