diff --git a/mistralclient/api/base.py b/mistralclient/api/base.py
index 44018e89..e25a0a2c 100644
--- a/mistralclient/api/base.py
+++ b/mistralclient/api/base.py
@@ -135,7 +135,8 @@ class ResourceManager(object):
 
     def _raise_api_exception(self, resp):
         try:
-            error_data = get_json(resp).get("faultstring")
+            error_data = (resp.headers.get("Server-Error-Message", None) or
+                          get_json(resp).get("faultstring"))
         except ValueError:
             error_data = resp.content
         raise APIException(error_code=resp.status_code,
diff --git a/mistralclient/tests/unit/base.py b/mistralclient/tests/unit/base.py
index 0ac01ff1..5989becb 100644
--- a/mistralclient/tests/unit/base.py
+++ b/mistralclient/tests/unit/base.py
@@ -24,6 +24,7 @@ class FakeResponse(object):
     def __init__(self, status_code, content=None):
         self.status_code = status_code
         self.content = content
+        self.headers = {}
 
     def json(self):
         return json.loads(self.content)