diff --git a/.github/workflows/validate_modified_targets.yml b/.github/workflows/validate_modified_targets.yml
index bb2445117..bff13ee59 100644
--- a/.github/workflows/validate_modified_targets.yml
+++ b/.github/workflows/validate_modified_targets.yml
@@ -47,6 +47,7 @@ jobs:
           # Safely extract the file from the PR's head and the merge-base commit
           git show pr:sherlock_project/resources/data.json > data.json.head
           git show $MERGE_BASE:sherlock_project/resources/data.json > data.json.base
+          git show $MERGE_BASE:sherlock_project/resources/data.schema.json > data.schema.json.base
 
           # CRITICAL FIX: Overwrite the checked-out data.json with the one from the PR
           # This ensures that pytest runs against the new, updated file.
@@ -59,15 +60,25 @@ jobs:
             python - <<'EOF'
           import json
           import sys
+          from jsonschema import validate, SchemaError, ValidationError
           try:
               with open("data.json.base") as f: base = json.load(f)
+              with open("data.schema.json.base") as f: schema = json.load(f)
               with open("data.json.head") as f: head = json.load(f)
+
+              validate(instance=head, schema=schema)
           except FileNotFoundError as e:
               print(f"Error: Could not find {e.filename}", file=sys.stderr)
               sys.exit(1)
           except json.JSONDecodeError as e:
               print(f"Error: Could not decode JSON from a file - {e}", file=sys.stderr)
               sys.exit(1)
+          except jsonschema.exceptions.SchemaError  as e:
+              print(f"Error: Could not locate local JSON schema for validation - {e}", file=sys.stderr)
+              sys.exit(1)
+          except jsonschema.exceptions.ValidationError  as e:
+              print(f"Error: Could not validate remote manifest against local schema - {e}", file=sys.stderr)
+              sys.exit(1)
 
           changed = []
           for k, v in head.items():