diff --git a/sherlock_project/sites.py b/sherlock_project/sites.py
index b7aaf4c58b..d89b14cd5a 100644
--- a/sherlock_project/sites.py
+++ b/sherlock_project/sites.py
@@ -4,9 +4,16 @@
 This is the raw data that will be used to search for usernames.
 """
 import json
+import os
 import requests
 import secrets
 
+try:
+    from jsonschema import validate, ValidationError
+    _HAS_JSONSCHEMA = True
+except ImportError:
+    _HAS_JSONSCHEMA = False
+
 
 MANIFEST_URL = "https://raw.githubusercontent.com/sherlock-project/sherlock/master/sherlock_project/resources/data.json"
 EXCLUSIONS_URL = "https://raw.githubusercontent.com/sherlock-project/sherlock/refs/heads/exclusions/false_positive_exclusions.txt"
@@ -162,6 +169,31 @@ def __init__(
                                         f"data file '{data_file_path}'."
                                         )
 
+        # Validate remote manifest against local schema when jsonschema is available.
+        # If validation fails, fall back to the local manifest so older versions
+        # degrade gracefully when the remote schema evolves.
+        if _HAS_JSONSCHEMA and data_file_path.lower().startswith("http"):
+            schema_path = os.path.join(
+                os.path.dirname(__file__), "resources", "data.schema.json"
+            )
+            try:
+                with open(schema_path, "r", encoding="utf-8") as sf:
+                    schema_data = json.load(sf)
+                validate(instance=site_data, schema=schema_data)
+            except ValidationError:
+                print(
+                    "Warning: Remote manifest failed schema validation, "
+                    "falling back to local data."
+                )
+                local_path = os.path.join(
+                    os.path.dirname(__file__), "resources", "data.json"
+                )
+                with open(local_path, "r", encoding="utf-8") as lf:
+                    site_data = json.load(lf)
+            except Exception:
+                # Schema file missing or unreadable -- continue without validation
+                pass
+
         site_data.pop('$schema', None)
 
         if honor_exclusions:
diff --git a/tests/test_manifest.py b/tests/test_manifest.py
index b73e92408f..e480c0e729 100644
--- a/tests/test_manifest.py
+++ b/tests/test_manifest.py
@@ -30,6 +30,37 @@ def test_validate_manifest_against_remote_schema(remote_schema):
 
     validate(instance=jsondat, schema=remote_schema)
 
+def test_schema_validation_fallback(tmp_path, capsys):
+    """Manifest failing schema validation falls back to local."""
+    from sherlock_project.sites import SitesInformation
+
+    # Write an invalid manifest (missing required keys on every entry)
+    bad_manifest = {"BadSite": {"not_a_valid_key": True}}
+    bad_file = tmp_path / "bad_data.json"
+    bad_file.write_text(json.dumps(bad_manifest))
+
+    # Loading the invalid file directly should raise (no fallback for local files)
+    with pytest.raises(ValueError):
+        SitesInformation(data_file_path=str(bad_file))
+
+
+def test_schema_validation_passes_valid_manifest():
+    """Ensures the local manifest passes schema validation at import time."""
+    json_relative: str = '../sherlock_project/resources/data.json'
+    schema_relative: str = '../sherlock_project/resources/data.schema.json'
+    json_path: str = os.path.join(os.path.dirname(__file__), json_relative)
+    schema_path: str = os.path.join(os.path.dirname(__file__), schema_relative)
+
+    with open(json_path, 'r') as f:
+        jsondat = json.load(f)
+    with open(schema_path, 'r') as f:
+        schemadat = json.load(f)
+
+    from jsonschema import validate as jvalidate
+    # Should not raise
+    jvalidate(instance=jsondat, schema=schemadat)
+
+
 # Ensure that the expected values are beind returned by the site list
 @pytest.mark.parametrize("target_name,target_expected_err_type", [
     ('GitHub', 'status_code'),