diff --git a/mimic/sources/har.py b/mimic/sources/har.py
index 7c446c2..e83c272 100644
--- a/mimic/sources/har.py
+++ b/mimic/sources/har.py
@@ -6,6 +6,7 @@ flow dicts so the rest of the pipeline (extract, hosts, endpoints, codegen)
 works unchanged, with no mitmproxy or iPhone setup at all.
 """
 import base64
+import binascii
 import json
 from urllib.parse import urlencode, urlparse
 
@@ -108,6 +109,6 @@ def _content_bytes(content):
     if content.get("encoding") == "base64":
         try:
             return base64.b64decode(text)
-        except ValueError:
+        except (binascii.Error, ValueError):
             return text.encode("utf-8")
     return text.encode("utf-8")
diff --git a/tests/test_har.py b/tests/test_har.py
index db9a025..c5cb2c4 100644
--- a/tests/test_har.py
+++ b/tests/test_har.py
@@ -80,3 +80,8 @@ def test_base64_response_body():
     assert '"ok"' in msg["response_body"]  # base64 "eyJvayI6IHRydWV9" -> {"ok": true}
     assert "true" in msg["response_body"]
     assert '"to"' in msg["request_body"]  # postData decoded too
+
+
+def test_invalid_base64_response_body_falls_back_to_text():
+    content = {"text": "not valid base64!", "encoding": "base64"}
+    assert har._content_bytes(content) == b"not valid base64!"