diff --git a/ChangeLog b/ChangeLog
index 7c2492f9..b5094fb9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -36,6 +36,12 @@
     Changed: linkcheck/linkparse.py, linkcheck/checker/urlbase.py
     Closes: SF bug #1831900
 
+  * Try to detect unkonwn URL schemes from the command line, eg. URLs
+    like "rtsp://foo".
+    Type: feature
+    Changed: linkchecker, linkcheck/lc_cgi.py,
+      linkcheck/checker/{__init__,urlbase,httpurl,unknownurl}.py
+
 4.7 "300" (released 17.6.2007)
 
   * Mention in the documentation that --anchors enables logging of
diff --git a/linkcheck/checker/__init__.py b/linkcheck/checker/__init__.py
index c9a7cada..3db4f3d3 100644
--- a/linkcheck/checker/__init__.py
+++ b/linkcheck/checker/__init__.py
@@ -151,7 +151,7 @@ def absolute_url (base_url, base_ref, parent_url):
 
 def get_url_from (base_url, recursion_level, aggregate,
                   parent_url=None, base_ref=None, line=0, column=0,
-                  name=u"", assume_local=False):
+                  name=u""):
     """
     Get url data from given base data.
 
@@ -180,13 +180,13 @@ def get_url_from (base_url, recursion_level, aggregate,
         base_ref = unicode_safe(base_ref)
     name = unicode_safe(name)
     url = absolute_url(base_url, base_ref, parent_url).lower()
-    klass = get_urlclass_from(url, assume_local)
+    klass = get_urlclass_from(url)
     return klass(base_url, recursion_level, aggregate,
                  parent_url=parent_url, base_ref=base_ref,
                  line=line, column=column, name=name)
 
 
-def get_urlclass_from (url, assume_local):
+def get_urlclass_from (url):
     """Return checker class for given URL."""
     if url.startswith("http:"):
         klass = linkcheck.checker.httpurl.HttpUrl
@@ -206,12 +206,12 @@ def get_urlclass_from (url, assume_local):
          url.startswith("news:") or \
          url.startswith("snews:"):
         klass = linkcheck.checker.nntpurl.NntpUrl
-    elif assume_local:
-        # assume local file
-        klass = linkcheck.checker.fileurl.FileUrl
-    else:
+    elif linkcheck.checker.unknownurl.is_unknown_url(url):
         # unknown url
         klass = linkcheck.checker.unknownurl.UnknownUrl
+    else:
+        # assume local file
+        klass = linkcheck.checker.fileurl.FileUrl
     return klass
 
 
diff --git a/linkcheck/checker/httpurl.py b/linkcheck/checker/httpurl.py
index 95b0c1e7..dc98f1fd 100644
--- a/linkcheck/checker/httpurl.py
+++ b/linkcheck/checker/httpurl.py
@@ -379,8 +379,7 @@ class HttpUrl (internpaturl.InternPatternUrl, proxysupport.ProxySupport):
                 newobj = linkcheck.checker.get_url_from(
                           redirected, self.recursion_level, self.aggregate,
                           parent_url=self.parent_url, base_ref=self.base_ref,
-                          line=self.line, column=self.column, name=self.name,
-                          assume_local=False)
+                          line=self.line, column=self.column, name=self.name)
                 # append new object to queue
                 self.aggregate.urlqueue.put(newobj)
                 # pretend to be finished and logged
diff --git a/linkcheck/checker/tests/__init__.py b/linkcheck/checker/tests/__init__.py
index c0bfbac0..84c83bc0 100644
--- a/linkcheck/checker/tests/__init__.py
+++ b/linkcheck/checker/tests/__init__.py
@@ -155,6 +155,16 @@ class LinkCheckTest (unittest.TestCase):
         """
         return linkcheck.url.url_norm(url)[0]
 
+    def get_attrs (self, **kwargs):
+        """Return current and data directory as dictionary.
+        You can augment the dict with keyword attributes."""
+        d = {
+            'curdir': linkcheck.checker.tests.get_file_url(os.getcwd()),
+            'datadir': "linkcheck/checker/tests/data",
+        }
+        d.update(kwargs)
+        return d
+
     def get_resultlines (self, filename):
         """
         Return contents of file, as list of lines without line endings,
@@ -170,7 +180,7 @@ class LinkCheckTest (unittest.TestCase):
         f.close()
         return resultlines
 
-    def file_test (self, filename, confargs=None, assume_local=True):
+    def file_test (self, filename, confargs=None):
         """
         Check <filename> with expected result in <filename>.result.
         """
@@ -179,9 +189,9 @@ class LinkCheckTest (unittest.TestCase):
             confargs = {}
         logargs = {'expected': self.get_resultlines(filename)}
         aggregate = get_test_aggregate(confargs, logargs)
-        url_data = get_url_from(url, 0, aggregate, assume_local=assume_local)
-        if assume_local:
-            linkcheck.add_intern_pattern(url_data, aggregate.config)
+        url_data = get_url_from(url, 0, aggregate)
+        # XXX if assume_local
+        linkcheck.add_intern_pattern(url_data, aggregate.config)
         aggregate.urlqueue.put(url_data)
         linkcheck.director.check_urls(aggregate)
         diff = aggregate.config['logger'].diff
@@ -192,7 +202,7 @@ class LinkCheckTest (unittest.TestCase):
             self.fail(l.encode("iso8859-1", "ignore"))
 
     def direct (self, url, resultlines, parts=None, recursionlevel=0,
-                confargs=None, assume_local=False):
+                confargs=None):
         """
         Check url with expected result.
         """
@@ -205,9 +215,9 @@ class LinkCheckTest (unittest.TestCase):
         if parts is not None:
             logargs['parts'] = parts
         aggregate = get_test_aggregate(confargs, logargs)
-        url_data = get_url_from(url, 0, aggregate, assume_local=assume_local)
-        if assume_local:
-            linkcheck.add_intern_pattern(url_data, aggregate.config)
+        url_data = get_url_from(url, 0, aggregate)
+        # XXX if assume_local:
+        linkcheck.add_intern_pattern(url_data, aggregate.config)
         aggregate.urlqueue.put(url_data)
         linkcheck.director.check_urls(aggregate)
         diff = aggregate.config['logger'].diff
diff --git a/linkcheck/checker/tests/test_error.py b/linkcheck/checker/tests/test_error.py
index e94d9fa8..4f3505a0 100644
--- a/linkcheck/checker/tests/test_error.py
+++ b/linkcheck/checker/tests/test_error.py
@@ -34,11 +34,12 @@ class TestError (linkcheck.checker.tests.LinkCheckTest):
         Unrecognized scheme test.
         """
         url = u"hutzli:"
-        nurl = self.norm(url)
+        attrs = self.get_attrs(url=url)
+        attrs['nurl'] = self.norm("file://%(curdir)s/%(url)s" % attrs)
         resultlines = [
-            u"url %s" % url,
-            u"cache key %s" % url,
-            u"real url %s" % nurl,
+            u"url %(nurl)s" % attrs,
+            u"cache key %(nurl)s" % attrs,
+            u"real url %(nurl)s" % attrs,
             u"error",
         ]
         self.direct(url, resultlines)
@@ -48,22 +49,22 @@ class TestError (linkcheck.checker.tests.LinkCheckTest):
         Leading whitespace test.
         """
         url = u" http://www.heise.de/"
-        nurl = self.norm(url)
+        attrs = self.get_attrs(url=url)
+        attrs['nurl'] = self.norm("file://%(curdir)s/%(url)s" % attrs)
         resultlines = [
-            u"url %s" % url,
-            u"cache key %s" % nurl,
-            u"real url %s" % nurl,
-            u"warning Base URL is not properly normed. Normed URL is %s." % nurl,
+            u"url %(nurl)s" % attrs,
+            u"cache key %(nurl)s" % attrs,
+            u"real url %(nurl)s" % attrs,
             u"error",
         ]
         self.direct(url, resultlines)
         url = u"\nhttp://www.heise.de/"
-        nurl = self.norm(url)
+        attrs = self.get_attrs(url=url)
+        attrs['nurl'] = self.norm("file://%(curdir)s/%(url)s" % attrs)
         resultlines = [
-            u"url %s" % url,
-            u"cache key %s" % nurl,
-            u"real url %s" % nurl,
-            u"warning Base URL is not properly normed. Normed URL is %s." % nurl,
+            u"url %(nurl)s" % attrs,
+            u"cache key %(nurl)s" % attrs,
+            u"real url %(nurl)s" % attrs,
             u"error",
         ]
         self.direct(url, resultlines)
@@ -96,12 +97,12 @@ class TestError (linkcheck.checker.tests.LinkCheckTest):
     def test_invalid1 (self):
         # invalid scheme chars
         url = u"äöü?:"
-        nurl = self.norm(url)
+        attrs = self.get_attrs(url=url)
+        attrs['nurl'] = self.norm("file://%(curdir)s/%(url)s" % attrs)
         resultlines = [
-            u"url %s" % url,
-            u"cache key %s" % nurl,
-            u"real url %s" % nurl,
-            u"warning Base URL is not properly normed. Normed URL is %s." % nurl,
+            u"url %(nurl)s" % attrs,
+            u"cache key %(nurl)s" % attrs,
+            u"real url %(nurl)s" % attrs,
             u"error",
         ]
         self.direct(url, resultlines)
@@ -109,12 +110,12 @@ class TestError (linkcheck.checker.tests.LinkCheckTest):
     def test_invalid2 (self):
         # missing scheme alltogether
         url = u"?äöü?"
-        nurl = self.norm(url)
+        attrs = self.get_attrs(url=url)
+        attrs['nurl'] = self.norm("file://%(curdir)s/%(url)s" % attrs)
         resultlines = [
-            u"url %s" % url,
-            u"cache key %s" % nurl,
-            u"real url %s" % nurl,
-            u"warning Base URL is not properly normed. Normed URL is %s." % nurl,
+            u"url %(nurl)s" % attrs,
+            u"cache key %(nurl)s" % attrs,
+            u"real url %(nurl)s" % attrs,
             u"error",
         ]
         self.direct(url, resultlines)
@@ -122,12 +123,12 @@ class TestError (linkcheck.checker.tests.LinkCheckTest):
     def test_invalid3 (self):
         # really fucked up
         url = u"@³²¼][½ ³@] ¬½"
-        nurl = self.norm(url)
+        attrs = self.get_attrs(url=url)
+        attrs['nurl'] = self.norm("file://%(curdir)s/%(url)s" % attrs)
         resultlines = [
-            u"url %s" % url,
-            u"cache key %s" % nurl,
-            u"real url %s" % nurl,
-            u"warning Base URL is not properly normed. Normed URL is %s." % nurl,
+            u"url %(nurl)s" % attrs,
+            u"cache key %(nurl)s" % attrs,
+            u"real url %(nurl)s" % attrs,
             u"error",
         ]
         self.direct(url, resultlines)
diff --git a/linkcheck/checker/tests/test_file.py b/linkcheck/checker/tests/test_file.py
index ed1b7168..965f06d8 100644
--- a/linkcheck/checker/tests/test_file.py
+++ b/linkcheck/checker/tests/test_file.py
@@ -23,13 +23,6 @@ import os
 
 import linkcheck.checker.tests
 
-def get_attrs ():
-    return {
-        'curdir': linkcheck.checker.tests.get_file_url(os.getcwd()),
-        'datadir': "linkcheck/checker/tests/data",
-    }
-
-
 class TestFile (linkcheck.checker.tests.LinkCheckTest):
     """
     Test file:// link checking (and file content parsing).
@@ -66,8 +59,7 @@ class TestFile (linkcheck.checker.tests.LinkCheckTest):
         self.file_test("urllist.txt")
 
     def test_good_file (self):
-        attrs = get_attrs()
-        url = u"file://%(curdir)s/%(datadir)s/file.txt" % attrs
+        url = u"file://%(curdir)s/%(datadir)s/file.txt" % self.get_attrs()
         nurl = self.norm(url)
         resultlines = [
             u"url %s" % url,
@@ -83,8 +75,7 @@ class TestFile (linkcheck.checker.tests.LinkCheckTest):
             # Cause: url get quoted %7C which gets lowercased to
             # %7c and this fails.
             return
-        attrs = get_attrs()
-        url = u"file:/%(curdir)s/%(datadir)s/file.txt" % attrs
+        url = u"file:/%(curdir)s/%(datadir)s/file.txt" % self.get_attrs()
         nurl = self.norm(url)
         resultlines = [
             u"url %s" % url,
@@ -96,7 +87,7 @@ class TestFile (linkcheck.checker.tests.LinkCheckTest):
 
     def test_good_file_missing_dslash (self):
         # good file (missing double slash)
-        attrs = get_attrs()
+        attrs = self.get_attrs()
         url = u"file:%(curdir)s/%(datadir)s/file.txt" % attrs
         nurl = self.norm(url)
         resultlines = [
@@ -109,8 +100,7 @@ class TestFile (linkcheck.checker.tests.LinkCheckTest):
         self.direct(url, resultlines)
 
     def test_good_dir (self):
-        attrs = get_attrs()
-        url = u"file://%(curdir)s/%(datadir)s/" % attrs
+        url = u"file://%(curdir)s/%(datadir)s/" % self.get_attrs()
         resultlines = [
             u"url %s" % url,
             u"cache key %s" % url,
diff --git a/linkcheck/checker/tests/test_http.py b/linkcheck/checker/tests/test_http.py
index fde593fc..6262afda 100644
--- a/linkcheck/checker/tests/test_http.py
+++ b/linkcheck/checker/tests/test_http.py
@@ -36,7 +36,7 @@ class TestHttp (httptest.HttpServerTest):
             url = u"http://localhost:%d/linkcheck/checker/tests/data/" \
                   u"http.html" % self.port
             resultlines = self.get_resultlines("http.html")
-            self.direct(url, resultlines, recursionlevel=1, assume_local=True)
+            self.direct(url, resultlines, recursionlevel=1)
             self.redirect1_http_test()
             self.redirect2_http_test()
             self.robots_txt_test()
@@ -69,7 +69,7 @@ class TestHttp (httptest.HttpServerTest):
             u"real url %s" % rurl,
             u"error",
         ]
-        self.direct(url, resultlines, recursionlevel=0, assume_local=True)
+        self.direct(url, resultlines, recursionlevel=0)
 
     def redirect1_http_test (self):
         url = u"http://localhost:%d/redirect1" % self.port
@@ -82,7 +82,7 @@ class TestHttp (httptest.HttpServerTest):
             u"info Redirected to %s." % rurl,
             u"error",
         ]
-        self.direct(url, resultlines, recursionlevel=0, assume_local=True)
+        self.direct(url, resultlines, recursionlevel=0)
 
     def redirect2_http_test (self):
         url = u"http://localhost:%d/linkcheck/checker/tests/data/redirect.html" % \
@@ -101,7 +101,7 @@ class TestHttp (httptest.HttpServerTest):
             u"name Recursive Redirect",
             u"valid",
         ]
-        self.direct(url, resultlines, recursionlevel=99, assume_local=True)
+        self.direct(url, resultlines, recursionlevel=99)
 
     def robots_txt_test (self):
         url = u"http://localhost:%d/robots.txt" % self.port
@@ -111,7 +111,7 @@ class TestHttp (httptest.HttpServerTest):
             u"real url %s" % url,
             u"valid",
         ]
-        self.direct(url, resultlines, recursionlevel=5, assume_local=True)
+        self.direct(url, resultlines, recursionlevel=5)
 
     def robots_txt2_test (self):
         url = u"http://localhost:%d/secret" % self.port
@@ -122,7 +122,7 @@ class TestHttp (httptest.HttpServerTest):
             u"warning Access denied by robots.txt, checked only syntax.",
             u"valid",
         ]
-        self.direct(url, resultlines, recursionlevel=5, assume_local=True)
+        self.direct(url, resultlines, recursionlevel=5)
 
     def noproxyfor_test (self):
         """
@@ -141,7 +141,7 @@ class TestHttp (httptest.HttpServerTest):
             u"valid",
         ]
         self.direct(url, resultlines, recursionlevel=0,
-                    confargs=confargs, assume_local=True)
+                    confargs=confargs)
         del os.environ["http_proxy"]
 
 
diff --git a/linkcheck/checker/unknownurl.py b/linkcheck/checker/unknownurl.py
index f4722a26..00f69712 100644
--- a/linkcheck/checker/unknownurl.py
+++ b/linkcheck/checker/unknownurl.py
@@ -60,6 +60,8 @@ acap        # application configuration access protocol
 
 ignored_schemes_re = re.compile(ignored_schemes, re.VERBOSE)
 
+is_unknown_url = ignored_schemes_re.search
+
 
 class UnknownUrl (urlbase.UrlBase):
     """
diff --git a/linkcheck/checker/urlbase.py b/linkcheck/checker/urlbase.py
index 2ef1f52d..7cc43113 100644
--- a/linkcheck/checker/urlbase.py
+++ b/linkcheck/checker/urlbase.py
@@ -672,8 +672,7 @@ class UrlBase (object):
             base_ref = linkcheck.url.url_norm(base_ref)[0]
             url_data = linkcheck.checker.get_url_from(url,
                   self.recursion_level+1, self.aggregate, parent_url=self.url,
-                  base_ref=base_ref, line=line, column=column, name=name,
-                  assume_local=False)
+                  base_ref=base_ref, line=line, column=column, name=name)
             self.aggregate.urlqueue.put(url_data)
 
     def parse_opera (self):
@@ -694,8 +693,7 @@ class UrlBase (object):
                 if url:
                     url_data = linkcheck.checker.get_url_from(url,
                               self.recursion_level+1, self.aggregate,
-                              parent_url=self.url, line=lineno, name=name,
-                              assume_local=False)
+                              parent_url=self.url, line=lineno, name=name)
                     self.aggregate.urlqueue.put(url_data)
                 name = ""
 
@@ -714,8 +712,7 @@ class UrlBase (object):
                 continue
             url_data = linkcheck.checker.get_url_from(line,
                               self.recursion_level+1, self.aggregate,
-                              parent_url=self.url, line=lineno,
-                              assume_local=False)
+                              parent_url=self.url, line=lineno)
             self.aggregate.urlqueue.put(url_data)
 
     def parse_css (self):
@@ -734,8 +731,7 @@ class UrlBase (object):
                 url = linkcheck.strformat.unquote(mo.group("url").strip())
                 url_data = linkcheck.checker.get_url_from(url,
                              self.recursion_level+1, self.aggregate,
-                             parent_url=self.url, line=lineno, column=column,
-                             assume_local=False)
+                             parent_url=self.url, line=lineno, column=column)
                 self.aggregate.urlqueue.put(url_data)
 
     def serialized (self):
diff --git a/linkcheck/lc_cgi.py b/linkcheck/lc_cgi.py
index 64795ae9..aa0514a5 100644
--- a/linkcheck/lc_cgi.py
+++ b/linkcheck/lc_cgi.py
@@ -95,7 +95,7 @@ def checklink (out=sys.stdout, form=None, env=os.environ):
     aggregate = linkcheck.director.get_aggregate(config)
     get_url_from = linkcheck.checker.get_url_from
     url = form["url"].value
-    url_data = get_url_from(url, 0, aggregate, assume_local=False)
+    url_data = get_url_from(url, 0, aggregate)
     try:
         linkcheck.add_intern_pattern(url_data, config)
     except UnicodeError:
diff --git a/linkchecker b/linkchecker
index a4b2a991..15213747 100755
--- a/linkchecker
+++ b/linkchecker
@@ -722,7 +722,7 @@ for url in args:
     elif url.lower().startswith("ftp."):
         # syntactic sugar
         url = "ftp://%s" % url
-    url_data = get_url_from(url, 0, aggregate, assume_local=True)
+    url_data = get_url_from(url, 0, aggregate)
     try:
         linkcheck.add_intern_pattern(url_data, config)
     except UnicodeError: