diff --git a/src/backend/core/recording/event/parsers.py b/src/backend/core/recording/event/parsers.py
index f99a07b0..1bdf3995 100644
--- a/src/backend/core/recording/event/parsers.py
+++ b/src/backend/core/recording/event/parsers.py
@@ -6,7 +6,7 @@ import re
 from dataclasses import dataclass
 from functools import lru_cache
 from typing import Any, Dict, Optional, Protocol
-from urllib.parse import quote_plus
+from urllib.parse import quote
 
 from django.conf import settings
 from django.utils.module_loading import import_string
@@ -165,8 +165,9 @@ class S3Parser(BaseS3Parser):
             if not filepath:
                 raise ParsingEventDataError("Missing object key name")
             filetype, _ = mimetypes.guess_type(filepath)
-            # Preserve already URL-encoded separators while encoding raw S3 object keys.
-            filepath = quote_plus(filepath, safe="%")
+            # Normalize raw S3-compatible object keys without re-encoding
+            # already encoded AWS S3 notification keys.
+            filepath = quote(filepath, safe="%+")
             return StorageEvent(
                 filepath=filepath,
                 filetype=filetype,
diff --git a/src/backend/core/tests/recording/event/test_parsers.py b/src/backend/core/tests/recording/event/test_parsers.py
index be2d2b47..e48b5bce 100644
--- a/src/backend/core/tests/recording/event/test_parsers.py
+++ b/src/backend/core/tests/recording/event/test_parsers.py
@@ -406,6 +406,32 @@ def test_s3_parser_accepts_unencoded_filepath(settings):
     assert parser.get_recording_id(data) == recording_id
 
 
+def test_s3_parser_preserves_plus_signs_in_raw_filepath(settings):
+    """Test S3 parser preserves plus signs while encoding slash separators."""
+    settings.RECORDING_OUTPUT_FOLDER = "recordings"
+
+    recording_id = "80ae9fe5-639a-438b-b86e-9e3dd2d55f4d"
+    parser = S3Parser(bucket_name="recordings-bucket")
+
+    data = {
+        "Records": [
+            {
+                "s3": {
+                    "bucket": {"name": "recordings-bucket"},
+                    "object": {
+                        "key": f"folder+name/recordings/{recording_id}.mp4",
+                    },
+                }
+            }
+        ]
+    }
+
+    event = parser.parse(data)
+
+    assert event.filepath == f"folder+name%2Frecordings%2F{recording_id}.mp4"
+    assert parser.validate(event) == recording_id
+
+
 def test_s3_get_recording_id_success(s3_parser, valid_s3_event):
     """Test successful extraction of recording ID from S3 event."""
     recording_id = s3_parser.get_recording_id(valid_s3_event)