diff --git a/python/cugraph/cugraph/community/louvain.py b/python/cugraph/cugraph/community/louvain.py
index f7798a8efbf..a37fe8d638f 100644
--- a/python/cugraph/cugraph/community/louvain.py
+++ b/python/cugraph/cugraph/community/louvain.py
@@ -101,6 +101,9 @@ def louvain(G, max_level=None, max_iter=None, resolution=1.0, threshold=1e-7):
     isolated_vertices = list()
     if is_nx_graph_type(type(G)):
         isolated_vertices = list(nx.isolates(G))
+    else:
+        # FIXME: Gather isolated vertices of G
+        pass
 
     G, isNx = ensure_cugraph_obj_for_nx(G)