diff --git a/pywb/rewrite/html_rewriter.py b/pywb/rewrite/html_rewriter.py
index bf28bf25..92c4e8e0 100644
--- a/pywb/rewrite/html_rewriter.py
+++ b/pywb/rewrite/html_rewriter.py
@@ -56,7 +56,7 @@ class HTMLRewriterMixin(StreamingRewriter):
                         'archive': 'oe_'},
             'area':    {'href': defmod},
             'audio':   {'src': 'oe_'},
-            'base':    {'href': defmod},
+            'base':    {'href': 'ba_'},
             'blockquote': {'cite': defmod},
             'body':    {'background': 'im_'},
             'button':  {'formaction': defmod},
diff --git a/pywb/rewrite/test/test_html_rewriter.py b/pywb/rewrite/test/test_html_rewriter.py
index 65bbfe28..26f12248 100644
--- a/pywb/rewrite/test/test_html_rewriter.py
+++ b/pywb/rewrite/test/test_html_rewriter.py
@@ -25,23 +25,23 @@ r"""
 
 # Base Tests -- w/ rewrite (default)
 >>> parse('<html><head><base href="http://example.com/diff/path/file.html"/>')
-<html><head><base href="/web/20131226101010/http://example.com/diff/path/file.html"/>
+<html><head><base href="/web/20131226101010ba_/http://example.com/diff/path/file.html"/>
 
 # Full Path
 >>> parse('<html><head><base href="http://example.com/diff/path/file.html"/>', urlrewriter=full_path_urlrewriter)
-<html><head><base href="http://localhost:80/web/20131226101010/http://example.com/diff/path/file.html"/>
+<html><head><base href="http://localhost:80/web/20131226101010ba_/http://example.com/diff/path/file.html"/>
 
 # Full Path Scheme Rel Base
 >>> parse('<base href="//example.com"/><img src="/foo.gif"/>', urlrewriter=full_path_urlrewriter)
-<base href="//localhost:80/web/20131226101010///example.com/"/><img src="/web/20131226101010im_/http://example.com/foo.gif"/>
+<base href="//localhost:80/web/20131226101010ba_///example.com/"/><img src="/web/20131226101010im_/http://example.com/foo.gif"/>
 
 # Rel Base
 >>> parse('<html><head><base href="/other/file.html"/>', urlrewriter=full_path_urlrewriter)
-<html><head><base href="/web/20131226101010/http://example.com/other/file.html"/>
+<html><head><base href="/web/20131226101010ba_/http://example.com/other/file.html"/>
 
 # Rel Base + example
 >>> parse('<html><head><base href="/other/file.html"/><a href="/path.html">', urlrewriter=full_path_urlrewriter)
-<html><head><base href="/web/20131226101010/http://example.com/other/file.html"/><a href="/web/20131226101010/http://example.com/path.html">
+<html><head><base href="/web/20131226101010ba_/http://example.com/other/file.html"/><a href="/web/20131226101010/http://example.com/path.html">
 
 # Rel Base
 >>> parse('<base href="./static/"/><img src="image.gif"/>', urlrewriter=full_path_urlrewriter)
@@ -53,7 +53,7 @@ r"""
 
 # ensure trailing slash added
 >>> parse('<base href="http://example.com"/>')
-<base href="/web/20131226101010/http://example.com/"/>
+<base href="/web/20131226101010ba_/http://example.com/"/>
 
 # Base Tests -- no rewrite
 >>> parse('<html><head><base href="http://example.com/diff/path/file.html"/>', urlrewriter=no_base_canon_rewriter)
@@ -244,29 +244,29 @@ r"""
 <div style="background: url('abc.html')" onblah on-click="location = 'redirect.html'"></div>
 
 >>> parse('<div style="background: url(\'/other_path/abc.html\')" onblah onclick="window.location = \'redirect.html\'"></div>')
-<div style="background: url('/web/20131226101010/http://example.com/other_path/abc.html')" onblah onclick="window.WB_wombat_location = 'redirect.html'"></div>
+<div style="background: url('/web/20131226101010ce_/http://example.com/other_path/abc.html')" onblah onclick="window.WB_wombat_location = 'redirect.html'"></div>
 
 >>> parse('<i style="background-image: url(http://foo-.bar_.example.com/)"></i>')
-<i style="background-image: url(/web/20131226101010/http://foo-.bar_.example.com/)"></i>
+<i style="background-image: url(/web/20131226101010ce_/http://foo-.bar_.example.com/)"></i>
 
 >>> parse('<i style=\'background-image: url("http://foo.example.com/")\'></i>')
-<i style="background-image: url(&quot;/web/20131226101010/http://foo.example.com/&quot;)"></i>
+<i style="background-image: url(&quot;/web/20131226101010ce_/http://foo.example.com/&quot;)"></i>
 
 >>> parse('<i style=\'background-image: url(&quot;http://foo.example.com/&quot;)\'></i>')
-<i style="background-image: url(&quot;/web/20131226101010/http://foo.example.com/&quot;)"></i>
+<i style="background-image: url(&quot;/web/20131226101010ce_/http://foo.example.com/&quot;)"></i>
 
 >>> parse('<i style=\'background-image: url(&#x27;http://foo.example.com/&#x27;)\'></i>')
 <i style="background-image: url('/web/20131226101010/http://foo.example.com/')"></i>
 
 >>> parse("<i style='background-image: url(&apos;http://foo.example.com/&apos;)'></i>")
-<i style="background-image: url(&apos;/web/20131226101010/http://foo.example.com/&apos;)"></i>
+<i style="background-image: url(&apos;/web/20131226101010ce_/http://foo.example.com/&apos;)"></i>
 
 #>>> parse('<i style=\'background-image: url(&quot;http://исп/&quot;)\'></i>')
 <i style="background-image: url(&quot;/web/20131226101010/http://%D0%B8%D1%81%D0%BF/&quot;)"></i>
 
 # Style
 >>> parse('<style>@import "/styles.css" .a { font-face: url(\'../myfont.ttf\') }</style>')
-<style>@import "/web/20131226101010/http://example.com/styles.css" .a { font-face: url('/web/20131226101010/http://example.com/some/myfont.ttf') }</style>
+<style>@import "/web/20131226101010cs_/http://example.com/styles.css" .a { font-face: url('/web/20131226101010ce_/http://example.com/some/myfont.ttf') }</style>
 
 # Unterminated style tag, handle and auto-terminate
 >>> parse('<style>@import url(styles.css)')
diff --git a/pywb/rewrite/test/test_regex_rewriters.py b/pywb/rewrite/test/test_regex_rewriters.py
index 786b9fd8..e59b8bf7 100644
--- a/pywb/rewrite/test/test_regex_rewriters.py
+++ b/pywb/rewrite/test/test_regex_rewriters.py
@@ -251,28 +251,28 @@ r"""
 #=================================================================
 
 >>> _test_css("background: url('/some/path.html')")
-"background: url('/web/20131010/http://example.com/some/path.html')"
+"background: url('/web/20131010ce_/http://example.com/some/path.html')"
 
 >>> _test_css("background: url('../path.html')")
-"background: url('/web/20131010/http://example.com/path.html')"
+"background: url('/web/20131010ce_/http://example.com/path.html')"
 
 >>> _test_css("background: url(\"http://domain.com/path.html\")")
-'background: url("/web/20131010/http://domain.com/path.html")'
+'background: url("/web/20131010ce_/http://domain.com/path.html")'
 
 >>> _test_css('background: url("   http://domain.com/path.html   ")')
-'background: url("   /web/20131010/http://domain.com/path.html   ")'
+'background: url("   /web/20131010ce_/http://domain.com/path.html   ")'
 
 >>> _test_css('background: url(" http://domain.com/path.html x ")')
-'background: url(" /web/20131010/http://domain.com/path.html x ")'
+'background: url(" /web/20131010ce_/http://domain.com/path.html x ")'
 
 >>> _test_css("background: url(file.jpeg)")
 'background: url(file.jpeg)'
 
 >>> _test_css("background:#abc url('/static/styles/../images/layout/logo.png')")
-"background:#abc url('/web/20131010/http://example.com/static/images/layout/logo.png')"
+"background:#abc url('/web/20131010ce_/http://example.com/static/images/layout/logo.png')"
 
 >>> _test_css("background:#000 url('/static/styles/../../images/layout/logo.png')")
-"background:#000 url('/web/20131010/http://example.com/images/layout/logo.png')"
+"background:#000 url('/web/20131010ce_/http://example.com/images/layout/logo.png')"
 
 >>> _test_css("background: url('')")
 "background: url('')"
@@ -281,7 +281,7 @@ r"""
 'background: url ("weirdpath\')'
 
 >>> _test_css("@import   url ('/path.css')")
-"@import   url ('/web/20131010/http://example.com/path.css')"
+"@import   url ('/web/20131010cs_/http://example.com/path.css')"
 
 >>> _test_css("@import url('path.css')")
 "@import url('path.css')"
@@ -290,19 +290,19 @@ r"""
 "@import ( 'path.css')"
 
 >>> _test_css("@import  \"/path.css\"")
-'@import  "/web/20131010/http://example.com/path.css"'
+'@import  "/web/20131010cs_/http://example.com/path.css"'
 
 >>> _test_css("@import ('../path.css\"")
-'@import (\'/web/20131010/http://example.com/path.css"'
+'@import (\'/web/20131010cs_/http://example.com/path.css"'
 
 >>> _test_css("@import ('../url.css\"")
-'@import (\'/web/20131010/http://example.com/url.css"'
+'@import (\'/web/20131010cs_/http://example.com/url.css"'
 
 >>> _test_css("@import (\"url.css\")")
 '@import ("url.css")'
 
 >>> _test_css("@import url(/url.css)\n@import  url(/anotherurl.css)\n @import  url(/and_a_third.css)")
-'@import url(/web/20131010/http://example.com/url.css)\n@import  url(/web/20131010/http://example.com/anotherurl.css)\n @import  url(/web/20131010/http://example.com/and_a_third.css)'
+'@import url(/web/20131010cs_/http://example.com/url.css)\n@import  url(/web/20131010cs_/http://example.com/anotherurl.css)\n @import  url(/web/20131010cs_/http://example.com/and_a_third.css)'
 
 """
 
