diff --git a/ariaec/commands.py b/ariaec/commands.py
index 5810c90bc61c9e4e6af8f69c45da9f8bb95e6385..d6a310c604c65b80d6602ecd161ec311f95e33c6 100644
--- a/ariaec/commands.py
+++ b/ariaec/commands.py
@@ -179,6 +179,8 @@ class AriaEcCommand:
         parser.add_argument("--ssidx", dest="ssidx", action="store_true",
                             default=False,
                             help="Use secondary structure index")
+        parser.add_argument("--prefix", dest="prefix", default="",
+                            help="File name")
         return parser
 
     def create_settings(self):
diff --git a/ariaec/commands.pyc b/ariaec/commands.pyc
index 147e2c4e6312fba904fbbfb1375c8b42188f957d..d08fd5a0a15f782f901970938d04ac47f6bafbcb 100644
Binary files a/ariaec/commands.pyc and b/ariaec/commands.pyc differ
diff --git a/ariaec/maplot.py b/ariaec/maplot.py
index 2be61d14ded7358034d234cc43a882f70412052f..5ca7ea7ba675c757b7c033c76e1601162d196c0a 100644
--- a/ariaec/maplot.py
+++ b/ariaec/maplot.py
@@ -36,7 +36,7 @@ class AriaEcContactMap(object):
                                             indent=4))
         # ----------------------------- Input -------------------------------- #
         self.outprefix = get_filename(self.settings.contactmap.args.get(
-            "seq", None))
+            "seq", None)) + self.settings.contactmap.args.get("prefix", "")
         # Load Sequence file
         self.protein.set_aa_sequence(self.settings.contactmap.args.get("seq", None))
         # Load secondary structure prediction file
diff --git a/ariaec/maplot.pyc b/ariaec/maplot.pyc
index 9309021709176257fae3c5271192e2a9f44936cd..13464f4d3d08ea40bcdb2c75f5d3a29295dc2a59 100644
Binary files a/ariaec/maplot.pyc and b/ariaec/maplot.pyc differ