diff --git a/src/python/jw/pkg/lib/Uri.py b/src/python/jw/pkg/lib/Uri.py
index cada582e..51534410 100644
--- a/src/python/jw/pkg/lib/Uri.py
+++ b/src/python/jw/pkg/lib/Uri.py
@@ -18,7 +18,12 @@ class Uri:
         if self.__p.path.startswith('~'):
             return self.path
         if scheme:
-            ret += f'{self.protocol}://'
+            if self.hostname is None and not self.path.startswith('/'):
+                # -- No authority and a relative path: '://' would
+                # re-parse the first path segment as a host
+                ret += f'{self.protocol}:'
+            else:
+                ret += f'{self.protocol}://'
         if credentials and self.username:
             ret += self.username
             if self.password:
@@ -156,6 +161,12 @@ class Uri:
         ret.__password = None
         if not path:
             return ret
+        if ret.__string.endswith('://'):
+            # -- Empty authority: the trailing '/' is part of the '://'
+            # separator, so a leading slash in path must be kept to stay
+            # an absolute path
+            ret.__string += path if path.startswith('/') else '/' + path
+            return ret
         if ret.__string[-1] == '/':
             if path[0] == '/':
                 ret.__string += path[1:]
diff --git a/test/unit/python/jw/pkg/lib/Uri/test.py b/test/unit/python/jw/pkg/lib/Uri/test.py
index a435b8b2..dc68b84f 100644
--- a/test/unit/python/jw/pkg/lib/Uri/test.py
+++ b/test/unit/python/jw/pkg/lib/Uri/test.py
@@ -21,6 +21,23 @@ assert '<hidden>' in u.safe_full_with_username  # safe version hides password
 u = Uri('/local/path')
 assert u.scheme == 'file'
 assert u.protocol == 'file'
+assert u.full == 'file:///local/path'
+
+# Relative paths default to file, too
+u = Uri('../../local/path')
+assert u.scheme == 'file'
+assert u.protocol == 'file'
+assert u.path == '../../local/path'
+
+# full keeps relative paths relative: '://' would re-parse the
+# first segment as a host
+assert u.full == 'file:../../local/path'
+assert Uri(u.full).path == '../../local/path'
+
+# An explicit file: scheme with a relative path round-trips, too
+u = Uri('file:../../local/path')
+assert u.path == '../../local/path'
+assert u.full == 'file:../../local/path'
 
 # Pimp returns existing Uri unchanged
 u1 = Uri('ssh://host/path')