diff --git a/matgl/graph/compute.py b/matgl/graph/compute.py
index c1ea20a3..43c34eb2 100644
--- a/matgl/graph/compute.py
+++ b/matgl/graph/compute.py
@@ -231,6 +231,10 @@ def ensure_directed_line_graph_compatibility(
     if line_graph.number_of_nodes() > sum(valid_edges):
         valid_edges = graph.edata["bond_dist"] <= threebody_cutoff + tol
 
+    # check again and raise if invalid
+    if line_graph.number_of_nodes() > sum(valid_edges):
+        raise RuntimeError("Line graph is not compatible with graph.")
+
     edge_ids = valid_edges.nonzero().squeeze()[: line_graph.number_of_nodes()]
     line_graph.ndata["edge_ids"] = edge_ids
 
diff --git a/tests/graph/test_compute.py b/tests/graph/test_compute.py
index d175a868..71cb3fae 100644
--- a/tests/graph/test_compute.py
+++ b/tests/graph/test_compute.py
@@ -260,5 +260,5 @@ def test_ensure_directed_line_graph_compat(graph_data, request):
     tt.assert_allclose(line_graph.ndata["edge_ids"], edge_ids)
     tt.assert_allclose(line_graph.ndata["src_bond_sign"], src_bond_sign)
 
-    with pytest.raises(AssertionError):
+    with pytest.raises(RuntimeError):
         ensure_directed_line_graph_compatibility(g, line_graph, 1.0)