diff --git a/src/py/crankshaft/crankshaft/clustering/kmeans.py b/src/py/crankshaft/crankshaft/clustering/kmeans.py
index e4fc7e5..383584e 100644
--- a/src/py/crankshaft/crankshaft/clustering/kmeans.py
+++ b/src/py/crankshaft/crankshaft/clustering/kmeans.py
@@ -92,9 +92,7 @@ def _extract_columns(db_resp, id_col_name):
         id_col_name (string): name of column which has the row id (not a
                               feature of the analysis)
     """
-    keys = [k for k in db_resp[0].keys()]
-
-    return np.array([db_resp[0][c] for c in keys
+    return np.array([db_resp[0][c] for c in db_resp.colnames()
                      if c != id_col_name],
                     dtype=float).T