diff --git a/rna_tools/tools/webserver-engine/app/templates/mutate.html b/rna_tools/tools/webserver-engine/app/templates/mutate.html
index d270768e3..535788129 100644
--- a/rna_tools/tools/webserver-engine/app/templates/mutate.html
+++ b/rna_tools/tools/webserver-engine/app/templates/mutate.html
@@ -278,8 +278,11 @@ <h5>Documentation</h5>
 </pre>
 yes, it was, the sequence for "_mutate.pdb" output file is now AGC.
 </p>
-
-     This is <a target="_new" href="https://rna-tools.readthedocs.io/en/latest/want.html?mutate-residues#mutate-residues">https://rna-tools.readthedocs.io/en/latest/want.html?mutate-residues#mutate-residues</a>
+<p>
+This tool works on multiple chains; for example, use 'A:1A,B:13A' to mutate the first residue of chain A into adenine and the first residue of chain B into adenine.
+</p>
+<p>
+This is <a target="_new" href="https://rna-tools.readthedocs.io/en/latest/want.html?mutate-residues#mutate-residues">https://rna-tools.readthedocs.io/en/latest/want.html?mutate-residues#mutate-residues</a>
 </p>
 
 <p>