diff --git a/.gitignore b/.gitignore
index ea06e23c..47acf0c4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,5 @@ dist/
 *egg*/
 docs/_build
 .project
+.pydevproject
+.settings/
diff --git a/flask_restless/helpers.py b/flask_restless/helpers.py
index 15e33ba8..7a18be84 100644
--- a/flask_restless/helpers.py
+++ b/flask_restless/helpers.py
@@ -213,6 +213,7 @@ def primary_key_names(model):
     """Returns all the primary keys for a model."""
     return [key for key, field in inspect.getmembers(model)
             if isinstance(field, QueryableAttribute)
+            and hasattr(field, 'property')
             and isinstance(field.property, ColumnProperty)
             and field.property.columns[0].primary_key]