diff --git a/src/icosagon/convlayer.py b/src/icosagon/convlayer.py
index d356afc..3fe1313 100644
--- a/src/icosagon/convlayer.py
+++ b/src/icosagon/convlayer.py
@@ -80,7 +80,10 @@ class DecagonLayer(torch.nn.Module):
                 repr_ = sum(repr_)
                 repr_ = torch.nn.functional.normalize(repr_, p=2, dim=1)
                 next_layer_repr[node_type_row].append(repr_)
-            next_layer_repr[node_type_row] = sum(next_layer_repr[node_type_row])
-            next_layer_repr[node_type_row] = self.layer_activation(next_layer_repr[node_type_row])
+            if len(next_layer_repr[node_type_row]) == 0:
+                next_layer_repr[node_type_row] = torch.zeros(self.output_dim[node_type_row])
+            else:
+                next_layer_repr[node_type_row] = sum(next_layer_repr[node_type_row])
+                next_layer_repr[node_type_row] = self.layer_activation(next_layer_repr[node_type_row])
 
         return next_layer_repr
diff --git a/src/icosagon/input.py b/src/icosagon/input.py
index 4f7dd73..8c686b1 100644
--- a/src/icosagon/input.py
+++ b/src/icosagon/input.py
@@ -16,7 +16,7 @@ class InputLayer(torch.nn.Module):
 
         output_dim = output_dim or \
             list(map(lambda a: a.count, data.node_types))
-            
+
         if not isinstance(output_dim, list):
             output_dim = [output_dim,] * len(data.node_types)
 
@@ -72,7 +72,7 @@ class OneHotInputLayer(torch.nn.Module):
 
     def __repr__(self) -> str:
         s = ''
-        s += 'One-hot Icosagon input layer\n'
+        s += 'Icosagon one-hot input layer\n'
         s += '  # of node types: %d\n' % len(self.data.node_types)
         for nt in self.data.node_types:
             s += '    - %s (%d)\n' % (nt.name, nt.count)
diff --git a/tests/icosagon/test_declayer.py b/tests/icosagon/test_declayer.py
index fb29831..2649759 100644
--- a/tests/icosagon/test_declayer.py
+++ b/tests/icosagon/test_declayer.py
@@ -43,8 +43,47 @@ def test_decode_layer_02():
     seq = torch.nn.Sequential(in_layer, d_layer, dec_layer)
 
     pred_adj_matrices = seq(None)
-    
+
     assert isinstance(pred_adj_matrices, dict)
     assert len(pred_adj_matrices) == 1
     assert isinstance(pred_adj_matrices[0, 0], list)
     assert len(pred_adj_matrices[0, 0]) == 1
+
+
+def test_decode_layer_03():
+    d = Data()
+    d.add_node_type('Dummy 1', 100)
+    d.add_node_type('Dummy 2', 100)
+    d.add_relation_type('Dummy Relation 1', 0, 1,
+        torch.rand((100, 100), dtype=torch.float32).round().to_sparse())
+
+    in_layer = OneHotInputLayer(d)
+    d_layer = DecagonLayer(in_layer.output_dim, 32, d)
+    dec_layer = DecodeLayer(input_dim=d_layer.output_dim, data=d, keep_prob=1.,
+        decoder_class={(0, 1): DEDICOMDecoder}, activation=lambda x: x)
+    seq = torch.nn.Sequential(in_layer, d_layer, dec_layer)
+
+    pred_adj_matrices = seq(None)
+    assert isinstance(pred_adj_matrices, dict)
+    assert len(pred_adj_matrices) == 2
+    assert isinstance(pred_adj_matrices[0, 1], list)
+    assert isinstance(pred_adj_matrices[1, 0], list)
+    assert len(pred_adj_matrices[0, 1]) == 1
+    assert len(pred_adj_matrices[1, 0]) == 1
+
+
+def test_decode_layer_04():
+    d = Data()
+    d.add_node_type('Dummy', 100)
+    assert len(d.relation_types[0, 0]) == 0
+
+    in_layer = OneHotInputLayer(d)
+    d_layer = DecagonLayer(in_layer.output_dim, 32, d)
+    dec_layer = DecodeLayer(input_dim=d_layer.output_dim, data=d, keep_prob=1.,
+        decoder_class=DEDICOMDecoder, activation=lambda x: x)
+    seq = torch.nn.Sequential(in_layer, d_layer, dec_layer)
+
+    pred_adj_matrices = seq(None)
+
+    assert isinstance(pred_adj_matrices, dict)
+    assert len(pred_adj_matrices) == 0
diff --git a/tests/icosagon/test_input.py b/tests/icosagon/test_input.py
index 3e73ce1..1e9cfbf 100644
--- a/tests/icosagon/test_input.py
+++ b/tests/icosagon/test_input.py
@@ -70,6 +70,13 @@ def test_input_layer_03():
     assert layer.node_reps[1].device == device
 
 
+def test_input_layer_04():
+    d = _some_data()
+    layer = InputLayer(d, 32)
+    s = repr(layer)
+    assert s.startswith('Icosagon input layer')
+
+
 def test_one_hot_input_layer_01():
     d = _some_data()
     layer = OneHotInputLayer(d)
@@ -104,3 +111,10 @@ def test_one_hot_input_layer_03():
     # assert layer.device.type == 'cuda:0'
     assert layer.node_reps[0].device == device
     assert layer.node_reps[1].device == device
+
+
+def test_one_hot_input_layer_04():
+    d = _some_data()
+    layer = OneHotInputLayer(d)
+    s = repr(layer)
+    assert s.startswith('Icosagon one-hot input layer')