diff --git a/tests/scripts/audit-validity-dates.py b/tests/scripts/audit-validity-dates.py
index ecde428..5506e40 100755
--- a/tests/scripts/audit-validity-dates.py
+++ b/tests/scripts/audit-validity-dates.py
@@ -302,12 +302,22 @@
             data = f.read()
 
         results = []
+        # Try to parse all PEM blocks.
+        is_pem = False
         for idx, m in enumerate(re.finditer(X509Parser.PEM_REGEX, data, flags=re.S), 1):
+            is_pem = True
             result = self.parse_bytes(data[m.start():m.end()])
             if result is not None:
                 result.locations.append("{}#{}".format(filename, idx))
                 results.append(result)
 
+        # Might be DER format.
+        if not is_pem:
+            result = self.parse_bytes(data)
+            if result is not None:
+                result.locations.append("{}".format(filename))
+                results.append(result)
+
         return results