diff --git a/src/warc2zim/content_rewriting/css.py b/src/warc2zim/content_rewriting/css.py
index be525997..534eada5 100644
--- a/src/warc2zim/content_rewriting/css.py
+++ b/src/warc2zim/content_rewriting/css.py
@@ -11,15 +11,23 @@
 from tinycss2.serializer import serialize_url
 
 from warc2zim.content_rewriting import UrlRewriterProto
-from warc2zim.content_rewriting.rx_replacer import RxRewriter, m2str
+from warc2zim.content_rewriting.rx_replacer import RxRewriter
 
 
 class FallbackRegexCssRewriter(RxRewriter):
     def __init__(self, url_rewriter: UrlRewriterProto):
         rules = [
             (
-                re.compile(r"""url\((?P<quote>['"])?.+?(?P=quote)(?<!\\)\)"""),
-                m2str(url_rewriter),
+                re.compile(r"""url\((?P<quote>['"])?(?P<url>.+?)(?P=quote)(?<!\\)\)"""),
+                lambda m_object, _opts: "".join(
+                    [
+                        "url(",
+                        m_object["quote"],
+                        url_rewriter(m_object["url"]),
+                        m_object["quote"],
+                        ")",
+                    ]
+                ),
             )
         ]
         super().__init__(rules)
@@ -28,6 +36,7 @@ def __init__(self, url_rewriter: UrlRewriterProto):
 class CssRewriter:
     def __init__(self, url_rewriter: UrlRewriterProto):
         self.url_rewriter = url_rewriter
+        self.fallback_rewriter = FallbackRegexCssRewriter(url_rewriter)
 
     def rewrite(self, content: str | bytes) -> str:
         if isinstance(content, bytes):
@@ -39,12 +48,7 @@ def rewrite(self, content: str | bytes) -> str:
         try:
             output = serialize(rules)
         except Exception:
-            fallback_rewriter = FallbackRegexCssRewriter(self.url_rewriter)
-            if isinstance(content, bytes):
-                content = content.decode()
-            return fallback_rewriter.rewrite_content(
-                content, {}  # pyright: ignore[reportArgumentType]
-            )
+            return self.fallback_rewriter.rewrite_content(content, {})
         return output
 
     def rewrite_inline(self, content: str) -> str:
@@ -54,8 +58,7 @@ def rewrite_inline(self, content: str) -> str:
             output = serialize(rules)
             return output
         except Exception:
-            fallback_rewriter = FallbackRegexCssRewriter(self.url_rewriter)
-            return fallback_rewriter.rewrite_content(content, {})
+            return self.fallback_rewriter.rewrite_content(content, {})
 
     def process_list(self, components: Iterable[ast.Node]):
         if components:  # May be null
diff --git a/tests/test_css_rewriting.py b/tests/test_css_rewriting.py
index 4b0266b3..1375ce9a 100644
--- a/tests/test_css_rewriting.py
+++ b/tests/test_css_rewriting.py
@@ -38,40 +38,68 @@ def no_rewrite_content(request):
 def test_no_rewrite(no_rewrite_content):
     assert (
         CssRewriter(ArticleUrlRewriter(no_rewrite_content.article_url, set())).rewrite(
-            no_rewrite_content.input_
+            no_rewrite_content.input_bytes
         )
-        == no_rewrite_content.expected.decode()
+        == no_rewrite_content.expected_bytes.decode()
     )
 
 
 @pytest.fixture(
     params=[
-        ContentForTests(b'"border:'),
-        ContentForTests(b"border: solid 1px #c0c0c0; width= 100%"),
-        ContentForTests(b"width:"),
-        ContentForTests(b"border-bottom-width: 1px;border-bottom-color: #c0c0c0;w"),
+        ContentForTests('"border:'),
+        ContentForTests("border: solid 1px #c0c0c0; width= 100%"),
+        # Despite being invalid, tinycss parse it as "width" property without value.
+        ContentForTests("width:", "width:;"),
+        ContentForTests("border-bottom-width: 1px;border-bottom-color: #c0c0c0;w"),
+        ContentForTests(
+            'background: url("http://exemple.com/foo.png"); width=',
+            'background: url("exemple.com/foo.png"); width=',
+        ),
     ]
 )
-def invalid_content(request):
+def invalid_content_inline(request):
     yield request.param
 
 
-def test_invalid_css(invalid_content):
+def test_invalid_css_inline(invalid_content_inline):
     assert (
-        CssRewriter(ArticleUrlRewriter(invalid_content.article_url, set())).rewrite(
-            invalid_content.input_
-        )
-        == invalid_content.expected.decode()
+        CssRewriter(
+            ArticleUrlRewriter(invalid_content_inline.article_url, set())
+        ).rewrite_inline(invalid_content_inline.input_str)
+        == invalid_content_inline.expected_str
     )
 
 
 @pytest.fixture(
-    params=[ContentForTests('p{background: url("http://exemple.com/foo.png"); width=}')]
+    params=[
+        # Tinycss parse `"border:}` as a string with an unexpected eof in string.
+        # At serialization, tiny try to recover and close the opened rule
+        ContentForTests(b'p {"border:}', b'p {"border:}}'),
+        ContentForTests(b'"p {border:}'),
+        ContentForTests(b"p { border: solid 1px #c0c0c0; width= 100% }"),
+        ContentForTests(b"p { width: }"),
+        ContentForTests(
+            b"p { border-bottom-width: 1px;border-bottom-color: #c0c0c0;w }"
+        ),
+        ContentForTests(
+            b'p { background: url("http://exemple.com/foo.png"); width= }',
+            b'p { background: url("exemple.com/foo.png"); width= }',
+        ),
+    ]
 )
-def invalid_and_rewrite(request):
+def invalid_content(request):
     yield request.param
 
 
+def test_invalid_cssl(invalid_content):
+    assert (
+        CssRewriter(ArticleUrlRewriter(invalid_content.article_url, set())).rewrite(
+            invalid_content.input_bytes
+        )
+        == invalid_content.expected_bytes.decode()
+    )
+
+
 def test_rewrite():
     content = b"""
 /* A comment with a link : http://foo.com */