diff --git a/tests/patch/kdoc/test.py b/tests/patch/kdoc/test.py
index e6d3216..e00307e 100644
--- a/tests/patch/kdoc/test.py
+++ b/tests/patch/kdoc/test.py
@@ -30,7 +30,8 @@ class KdocWarning:
     # Note: *not* part of comparison, or hash!
     line : Optional[int] = dataclasses.field(repr=True, compare=False)
     # The content of the warning (excluding kind, file, line)
-    content : str = dataclasses.field(repr=True, compare=True)
+    content : Optional[str] = dataclasses.field(repr=True, compare=True)
+    parsed : bool = dataclasses.field(repr=True, compare=True)
 
     @classmethod
     def from_text(self, line, extra=None):
@@ -60,14 +61,35 @@ def from_text(self, line, extra=None):
             content = m['content']
             if extra:
                 content += '\n' + extra
-        else:
-            kind = 'Unknown'
-            file = None
-            line = None
-            content = message
 
-        return KdocWarning(message, kind=kind, file=file, line=line,
-                           content=content)
+            return KdocWarning(message, kind=kind, file=file, line=line,
+                               content=content, parsed=True)
+
+        # Check for line-number only warnings produced by certain buggy
+        # versions of kernel-doc. These will get treated as unparsed but
+        # all such warnings will compare identically to each other.
+        line_only_parser = re.compile(
+            r"""
+            ^                         # Start of string
+            (?P<kind>warning|error):  # Severity
+            \s+                       # Spacing
+            (?P<line>[0-9]+)          # Line number
+            $                         # End of string
+            """,
+            re.VERBOSE | re.IGNORECASE)
+
+        m = line_only_parser.match(line)
+        if m:
+            kind = m['kind']
+            line = m['line']
+
+            return KdocWarning(message, kind=kind, file=None, line=line,
+                               content=None, parsed=False)
+
+        # The warning text didn't match a known format. Such warnings will be
+        # counted to ensure that we don't increase this count over time.
+        return KdocWarning(message, kind='Unknown', file=None, line=None,
+                           content=line, parsed=False)
 
     def __str__(self):
         return self.message
@@ -80,20 +102,28 @@ def parse_warnings(lines, logs) -> List[KdocWarning]:
 
     # Walk through lines and convert to warning objects
     for i, line in enumerate(lines):
+        # Skip lines already merged into previous warning
         if skip:
             skip = False
             continue
 
+        # Ignore blank lines
+        if not line.strip():
+            continue
+
+        # Check if we should merge the next line with this warning
+        extra = None
         if line.endswith(':') and i + 1 < length:
             extra = lines[i + 1]
             skip = True
-        elif not line.strip():
-            continue
-        else:
-            logs += ["<parse fail>: " + line.strip()]
-            extra = None
 
-        warnings.append(KdocWarning.from_text(line, extra))
+        # Parse line into warning object
+        warning = KdocWarning.from_text(line, extra);
+
+        if not warning.parsed:
+            logs += [f'<parse fail>: {line.strip()}']
+
+        warnings.append(warning)
 
     return warnings
 
@@ -181,6 +211,10 @@ def kdoc(tree, patch, _result_dir) -> Tuple[int, str, str]:
     new_count = len(new_warnings)
     rm_count = len(rm_warnings)
 
+    # Count the number of warnings which we failed to parse
+    current_unparsed = len([x for x in current_warnings if not x.parsed])
+    incumbent_unparsed = len([x for x in incumbent_warnings if not x.parsed])
+
     desc = f'Warnings before: {incumbent_count} after: {current_count}'
     brac = []
     if new_count:
@@ -213,4 +247,8 @@ def kdoc(tree, patch, _result_dir) -> Tuple[int, str, str]:
         for f, count in file_breakdown.items():
             log += [f'{count:6} {f}']
 
+    if current_unparsed > incumbent_unparsed:
+        ret = 1
+        log += ["", f'Number of parse failures increased from {incumbent_unparsed} to {current_unparsed}.']
+
     return ret, desc, "\n".join(log)