pick only the specified package from buster-backports instead of choosing a default suite

howto/fabric.md

@@ -153,7 +153,7 @@ you should install the newer, 2.x version that is only available in
 bullseye and later. The bullseye version is a "trivial backport" which
 means it can be installed directly in stable with:
 
-    apt install -t bullseye fabric
+    apt install fabric/buster-backports
 
 [part of Debian since at least Debian jessie]: https://tracker.debian.org/pkg/fabric
 
@@ -162,7 +162,7 @@ This will also pull [invoke](https://tracker.debian.org/pkg/python-invoke) (from
 by default, however, so you might want to upgrade to backports as
 well:
 
-    apt install -t buster-backports python3-paramiko
+    apt install python3-paramiko/buster-backports
 
 ## SLA