diff --git a/requests/exceptions.py b/requests/exceptions.py
index d8f05f0817..34c7a0dbff 100644
--- a/requests/exceptions.py
+++ b/requests/exceptions.py
@@ -89,3 +89,6 @@ class ChunkedEncodingError(RequestException):
 
 class ContentDecodingError(RequestException, BaseHTTPError):
     """Failed to decode response content"""
+
+class StreamConsumedError(RequestException, TypeError):
+    """The content for this response was already consumed"""
diff --git a/requests/models.py b/requests/models.py
index bbf08c8135..897cd6fd66 100644
--- a/requests/models.py
+++ b/requests/models.py
@@ -22,8 +22,9 @@
 from .packages.urllib3.exceptions import (
     DecodeError, ReadTimeoutError, ProtocolError)
 from .exceptions import (
-    HTTPError, RequestException, MissingSchema, InvalidURL,
-    ChunkedEncodingError, ContentDecodingError, ConnectionError)
+    HTTPError, RequestException, MissingSchema, InvalidURL, 
+    ChunkedEncodingError, ContentDecodingError, ConnectionError, 
+    StreamConsumedError)
 from .utils import (
     guess_filename, get_auth_from_url, requote_uri,
     stream_decode_response_unicode, to_key_val_list, parse_header_links,
@@ -655,6 +656,8 @@ def generate():
 
             self._content_consumed = True
 
+        if self._content_consumed and isinstance(self._content, bool):
+            raise StreamConsumedError()
         # simulate reading small chunks of the content
         reused_chunks = iter_slices(self._content, chunk_size)