diff --git a/tests/loaders/test_file_loader_http_fallback.py b/tests/loaders/test_file_loader_http_fallback.py
index b7ee52876..820f9a0bc 100644
--- a/tests/loaders/test_file_loader_http_fallback.py
+++ b/tests/loaders/test_file_loader_http_fallback.py
@@ -31,6 +31,7 @@ async def dummy_file_load(
         successful=True,
         buffer="file",
     )
+
     return result
 
 
@@ -41,6 +42,7 @@ async def dummy_http_load(
         successful=True,
         buffer="http",
     )
+
     return result
 
 
@@ -70,3 +72,18 @@ async def test_should_load_http(self):
 
         expect(result).to_be_instance_of(LoaderResult)
         expect(result.buffer).to_equal("http")
+
+    @patch.object(thumbor.loaders.http_loader, "load", dummy_http_load)
+    @gen_test
+    async def test_should_fail_with_disallowed_origin(self):
+        url = "http:/www.google.com/example_image.png"
+        config = Config(ALLOWED_SOURCES=[".+.domain1.com"])
+        ctx = Context(None, config, None)
+
+        result = await loader.load(ctx, url)
+
+        expect(result).to_be_instance_of(LoaderResult)
+        expect(result.successful).to_be_false()
+        expect(result.error).to_equal(LoaderResult.ERROR_BAD_REQUEST)
+        expect(result.extras["reason"]).to_equal("Unallowed domain")
+        expect(result.extras["source"]).to_equal(url)
diff --git a/thumbor/loaders/__init__.py b/thumbor/loaders/__init__.py
index d2eed95cb..b4f1fcca3 100644
--- a/thumbor/loaders/__init__.py
+++ b/thumbor/loaders/__init__.py
@@ -8,14 +8,24 @@
 # http://www.opensource.org/licenses/mit-license
 # Copyright (c) 2011 globo.com thumbor@googlegroups.com
 
+from typing import Dict
+
 
 class LoaderResult:
 
     ERROR_NOT_FOUND = "not_found"
     ERROR_UPSTREAM = "upstream"
     ERROR_TIMEOUT = "timeout"
-
-    def __init__(self, buffer=None, successful=True, error=None, metadata=None):
+    ERROR_BAD_REQUEST = "bad_request"
+
+    def __init__(
+        self,
+        buffer: bytes = None,
+        successful: bool = True,
+        error: str = None,
+        metadata: Dict[str, any] = None,
+        extras: Dict[str, any] = None,
+    ):
         """
         :param buffer: The media buffer
 
@@ -27,12 +37,19 @@ def __init__(self, buffer=None, successful=True, error=None, metadata=None):
 
         :param metadata: Dictionary of metadata about the buffer
         :type metadata: dict
+
+        :param extras: Dictionary of extra information about the error
+        :type metadata: dict
         """
 
         if metadata is None:
             metadata = {}
 
+        if extras is None:
+            extras = {}
+
         self.buffer = buffer
         self.successful = successful
         self.error = error
         self.metadata = metadata
+        self.extras = extras
diff --git a/thumbor/loaders/file_loader_http_fallback.py b/thumbor/loaders/file_loader_http_fallback.py
index 816e133a0..f18329e63 100644
--- a/thumbor/loaders/file_loader_http_fallback.py
+++ b/thumbor/loaders/file_loader_http_fallback.py
@@ -8,14 +8,25 @@
 # http://www.opensource.org/licenses/mit-license
 # Copyright (c) 2011 globo.com thumbor@googlegroups.com
 
-from thumbor.loaders import file_loader, http_loader
+from thumbor.loaders import LoaderResult, file_loader, http_loader
 
 
 async def load(context, path):
     # First attempt to load with file_loader
     result = await file_loader.load(context, path)
+
     if result.successful:
         return result
 
     # If file_loader failed try http_loader
+
+    if not http_loader.validate(context, path):
+        result = LoaderResult()
+        result.successful = False
+        result.error = LoaderResult.ERROR_BAD_REQUEST
+        result.extras["reason"] = "Unallowed domain"
+        result.extras["source"] = path
+
+        return result
+
     return await http_loader.load(context, path)