diff --git a/bin/xbps-install/xbps-install.1 b/bin/xbps-install/xbps-install.1
index 96eebbed..61e8c423 100644
--- a/bin/xbps-install/xbps-install.1
+++ b/bin/xbps-install/xbps-install.1
@@ -99,7 +99,9 @@ than looking in the target root directory.
 Appends the specified repository to the top of the list. The
 .Ar url
 argument expects a URL to the repository for remote repositories or
-a path for local repositories.
+a path for local repositories. Note that remote repositories must be signed
+using
+.Xr xbps-rindex 1 .
 This option can be specified multiple times.
 .It Fl r, Fl -rootdir Ar dir
 Specifies a full path for the target root directory.
diff --git a/bin/xbps-query/xbps-query.1 b/bin/xbps-query/xbps-query.1
index 5d14d16a..0d9c222f 100644
--- a/bin/xbps-query/xbps-query.1
+++ b/bin/xbps-query/xbps-query.1
@@ -83,7 +83,9 @@ than looking in the target root directory.
 Appends the specified repository to the top of the list. The
 .Ar url
 argument expects a URL to the repository for remote repositories or
-a path for local repositories.
+a path for local repositories.  Note that remote repositories must be signed
+using
+.Xr xbps-rindex 1 .
 This option can be specified multiple times.
 .It Fl -regex
 Enables string matching by using Extended Regular Expressions in compatible modes,
diff --git a/data/xbps.d.5 b/data/xbps.d.5
index 71c8951e..e4a7f970 100644
--- a/data/xbps.d.5
+++ b/data/xbps.d.5
@@ -74,7 +74,10 @@ Declares a package repository. The
 argument accepts local and remote repositories.
 A complete url or absolute path to the directory that stores the
 .Em <arch>-repodata
-archive is expected, example:
+archive is expected.
+Note that remote repositories must be signed using
+.Xr xbps-rindex 1 ,
+example:
 .Pp
 .Bl -tag -compact -width repository=http://repo.voidlinux.eu/current
 .It Sy repository=http://repo.voidlinux.eu/current