diff --git a/swh/loader/svn/tests/test_utils.py b/swh/loader/svn/tests/test_utils.py
--- a/swh/loader/svn/tests/test_utils.py
+++ b/swh/loader/svn/tests/test_utils.py
@@ -352,12 +352,24 @@
             "http://svn.example.org/repos/test",
             ("external", "http://svn.thirdparty.com/repos/test", None, False),
         ),
+        (
+            "external/ http://svn.thirdparty.com/repos/test",
+            "tags",
+            "http://svn.example.org/repos/test",
+            ("external", "http://svn.thirdparty.com/repos/test", None, False),
+        ),
         (
             "external ttp://svn.thirdparty.com/repos/test",
             "tags",
             "http://svn.example.org/repos/test",
             ("external", "ttp://svn.thirdparty.com/repos/test", None, False),
         ),
+        (
+            "external http//svn.thirdparty.com/repos/test",
+            "tags",
+            "http://svn.example.org/repos/test",
+            ("external", "http//svn.thirdparty.com/repos/test", None, False),
+        ),
         (
             "C:\\code\\repo\\external http://svn.thirdparty.com/repos/test",
             "tags",
diff --git a/swh/loader/svn/utils.py b/swh/loader/svn/utils.py
--- a/swh/loader/svn/utils.py
+++ b/swh/loader/svn/utils.py
@@ -253,7 +253,7 @@
             # property is set
             external_url = svn_urljoin(repo_url, dir_path, external_part)
             relative_url = not external_url.startswith(repo_url)
-        elif re.match(r"^.*://.*", external_part):
+        elif re.match(r"^.*:*//.*", external_part):
             # absolute external URL
             external_url = external_part
         # subversion >= 1.6 added a quoting and escape mechanism to the syntax so
@@ -291,4 +291,4 @@
         except ValueError:
             # handle URL like http://user@svn.example.org/
             pass
-    return (path, external_url, revision, relative_url)
+    return (path.rstrip("/"), external_url, revision, relative_url)