diff --git a/bin/align/phyluce_align_concatenate_alignments b/bin/align/phyluce_align_concatenate_alignments
index 3fb8845..62fba4a 100755
--- a/bin/align/phyluce_align_concatenate_alignments
+++ b/bin/align/phyluce_align_concatenate_alignments
@@ -41,7 +41,7 @@ def get_args():
     parser.add_argument(
         "--input-format",
         dest="input_format",
-        choices=["fasta", "nexus", "phylip", "clustal", "emboss", "stockholm"],
+        choices=["fasta", "nexus", "phylip", "phylip-relaxed", "clustal", "emboss", "stockholm"],
         default="nexus",
         help="""The input alignment format""",
     )