diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index 7338e61..9ab7b9d 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -296,12 +296,6 @@ def _decode_result(response, decoders, force_codec=False):
         # No content returned in response.
         result = None
 
-    # Coerce 4xx and 5xx codes into errors.
-    is_error = response.status_code >= 400 and response.status_code <= 599
-    if is_error and not isinstance(result, Error):
-        default_title = '%d %s' % (response.status_code, response.reason)
-        result = _coerce_to_error(result, default_title=default_title)
-
     return result
 
 
@@ -378,6 +372,7 @@ def transition(self, link, decoders, params=None, link_ancestors=None, force_cod
         request = _build_http_request(session, url, method, headers, encoding, params)
         settings = session.merge_environment_settings(request.url, None, None, None, None)
         response = session.send(request, **settings)
+        response.raise_for_status()
         result = _decode_result(response, decoders, force_codec)
 
         if isinstance(result, Document) and link_ancestors:
diff --git a/tests/test_integration.py b/tests/test_integration.py
index 0a2e602..31661f5 100644
--- a/tests/test_integration.py
+++ b/tests/test_integration.py
@@ -23,6 +23,9 @@ def __init__(self, content):
         self.url = 'http://example.org'
         self.status_code = 200
 
+    def raise_for_status(self):
+        pass
+
 
 # Basic integration tests.
 
diff --git a/tests/test_transport.py b/tests/test_transport.py
index eeeb17a..8038edb 100644
--- a/tests/test_transport.py
+++ b/tests/test_transport.py
@@ -26,6 +26,9 @@ def __init__(self, content):
         self.url = 'http://example.org'
         self.status_code = 200
 
+    def raise_for_status(self):
+        pass
+
 
 # Test transport errors.