diff --git a/jobs/templates/swh-docs-pipeline-diff.groovy.j2 b/jobs/templates/swh-docs-pipeline-diff.groovy.j2
--- a/jobs/templates/swh-docs-pipeline-diff.groovy.j2
+++ b/jobs/templates/swh-docs-pipeline-diff.groovy.j2
@@ -32,8 +32,8 @@
           sh'''#!/bin/bash
           crudini --del .mrconfig snippets
           crudini --del .mrconfig swh-py-template
-          # force shallow clone of swh-repos except swh-docs
-          sed -i '/swh-docs/!s/git clone/git clone --depth 1/g' .mrconfig
+          # only fetch the HEAD branch instead of all (potentially large) branches
+          sed -i '/swh-docs/!s/git clone/git clone --single-branch/g' .mrconfig
           mr -j 4 -t update
           '''
         }
@@ -113,4 +113,4 @@
       cleanWs()
     }
   }
-}
\ No newline at end of file
+}