diff --git a/hgext/convert/__init__.py b/hgext/convert/__init__.py
--- a/hgext/convert/__init__.py
+++ b/hgext/convert/__init__.py
@@ -356,6 +356,9 @@ def convert(ui, src, dest=None, revmapfi
     :convert.hg.usebranchnames: preserve branch names. The default is
         True.
 
+    :convert.hg.sourcename: records the given string as a 'convert_source' extra
+        value on each commit made in the target repository. The default is None.
+
     All Destinations
     ################
 
diff --git a/hgext/convert/hg.py b/hgext/convert/hg.py
--- a/hgext/convert/hg.py
+++ b/hgext/convert/hg.py
@@ -225,6 +225,10 @@ class mercurial_sink(converter_sink):
 
         extra = commit.extra.copy()
 
+        sourcename = self.repo.ui.config('convert', 'hg.sourcename')
+        if sourcename:
+            extra['convert_source'] = sourcename
+
         for label in ('source', 'transplant_source', 'rebase_source',
                       'intermediate-source'):
             node = extra.get(label)
diff --git a/tests/test-convert.t b/tests/test-convert.t
--- a/tests/test-convert.t
+++ b/tests/test-convert.t
@@ -294,6 +294,10 @@
                     branch name for tag revisions, defaults to "default".
       convert.hg.usebranchnames
                     preserve branch names. The default is True.
+      convert.hg.sourcename
+                    records the given string as a 'convert_source' extra value
+                    on each commit made in the target repository. The default is
+                    None.
   
       All Destinations
       ################
@@ -503,3 +507,17 @@ test revset converted() lookup
   date:        Thu Jan 01 00:00:04 1970 +0000
   summary:     e
   
+
+test specifying a sourcename
+  $ echo g > a/g
+  $ hg -R a ci -d'0 0' -Amg
+  adding g
+  $ hg --config convert.hg.sourcename=mysource --config convert.hg.saverev=True convert a c
+  scanning source...
+  sorting...
+  converting...
+  0 g
+  $ hg -R c log -r tip --template '{extras % "{extra}\n"}'
+  branch=default
+  convert_revision=a3bc6100aa8ec03e00aaf271f1f50046fb432072
+  convert_source=mysource