diff --git a/src/pg/sql/11_kmeans.sql b/src/pg/sql/11_kmeans.sql
index 6a9d1a9..175ab6b 100644
--- a/src/pg/sql/11_kmeans.sql
+++ b/src/pg/sql/11_kmeans.sql
@@ -15,14 +15,14 @@ CREATE OR REPLACE FUNCTION CDB_KMeansNonspatial(
   query TEXT,
   colnames TEXT[],
   num_clusters INTEGER,
-  id_col TEXT DEFAULT 'cartodb_id',
+  id_colname TEXT DEFAULT 'cartodb_id',
   standarize BOOLEAN DEFAULT true
 )
-RETURNS TABLE(cluster_label text, cluster_center text, rowid bigint) AS $$
+RETURNS TABLE(cluster_label text, cluster_center json, rowid bigint) AS $$
 
     from crankshaft.clustering import kmeans_nonspatial
     return kmeans_nonspatial(query, colnames, num_clusters,
-                             id_col, standarize)
+                             id_colname, standarize)
 $$ LANGUAGE plpythonu;
 
 
diff --git a/src/py/crankshaft/crankshaft/clustering/kmeans.py b/src/py/crankshaft/crankshaft/clustering/kmeans.py
index 6e972e5..5bd7830 100644
--- a/src/py/crankshaft/crankshaft/clustering/kmeans.py
+++ b/src/py/crankshaft/crankshaft/clustering/kmeans.py
@@ -40,6 +40,7 @@ def kmeans_nonspatial(query, colnames, num_clusters=5,
         num_clusters (int): number of clusters (greater than zero)
         id_col (string): name of the input id_column
     """
+    import json
     out_id_colname = 'rowids'
     # TODO: need a random seed?
 
@@ -60,7 +61,7 @@ def kmeans_nonspatial(query, colnames, num_clusters=5,
     # fill array with values for k-means clustering
     if standarize:
         cluster_columns = _scale_data(
-          _extract_columns(db_resp, id_col=out_id_colname))
+          _extract_columns(db_resp, out_id_colname))
     else:
         cluster_columns = _extract_columns(db_resp, id_col=out_id_colname)
 
@@ -69,8 +70,9 @@ def kmeans_nonspatial(query, colnames, num_clusters=5,
     kmeans = KMeans(n_clusters=num_clusters,
                     random_state=0).fit(cluster_columns)
 
+    centers = [json.dumps(dict(zip(colnames, c))) for c in kmeans.cluster_centers_[kmeans.labels_]]
     return zip(kmeans.labels_,
-               map(str, kmeans.cluster_centers_[kmeans.labels_]),
+               centers,
                db_resp[0][out_id_colname])