diff --git a/mithril/framework/logical/model.py b/mithril/framework/logical/model.py
index d13fb87e..ecc8d714 100644
--- a/mithril/framework/logical/model.py
+++ b/mithril/framework/logical/model.py
@@ -849,20 +849,21 @@ def extend(
         # Update Canonicals
         if isinstance(c_input := model.canonical_input, Connection):
             c_input_obj = self.conns.get_con_by_metadata(c_input.data.metadata)
-            if c_input_obj not in self.dependency_map._local_output_dependency_map:
-                # Update canonical input with model canonical input
-                if c_input_obj not in self.conns.input_connections:
-                    self._canonical_input = NOT_AVAILABLE
-                else:
-                    assert c_input_obj is not None
-                    self._canonical_input = c_input_obj
+            if c_input_obj is not None and c_input_obj.metadata.data.value is TBD:
+                if c_input_obj not in self.dependency_map._local_output_dependency_map:
+                    # Update canonical input with model canonical input
+                    if c_input_obj not in self.conns.input_connections:
+                        self._canonical_input = NOT_AVAILABLE
+                    else:
+                        assert c_input_obj is not None
+                        self._canonical_input = c_input_obj
 
-            elif (
-                self._canonical_input
-                in self.dependency_map._local_output_dependency_map
-            ):
-                # Model canonical output used as input than make it None
-                self._canonical_input = NOT_AVAILABLE
+                elif (
+                    self._canonical_input
+                    in self.dependency_map._local_output_dependency_map
+                ):
+                    # Model canonical output used as input than make it None
+                    self._canonical_input = NOT_AVAILABLE
 
         if isinstance(c_output := model.canonical_output, Connection):
             c_output_obj = self.conns.get_con_by_metadata(c_output.data.metadata)
diff --git a/tests/scripts/test_scripts.py b/tests/scripts/test_scripts.py
index b4a9048d..e1de9596 100644
--- a/tests/scripts/test_scripts.py
+++ b/tests/scripts/test_scripts.py
@@ -952,6 +952,36 @@ def test_canonical_input_9():
     assert model.canonical_output == model.output  # type: ignore
 
 
+def test_canonical_input_10():
+    # Valued cannection cannot be canonical input
+    model = Model()
+    model += Add()(left=3, right="input2", output="output")
+
+    assert model.canonical_input is NOT_AVAILABLE
+
+
+def test_canonical_input_11():
+    # Valued cannection cannot be canonical input
+    model = Model()
+    model += (buff := Buffer())
+    model += Add()(left=3, right="input2", output="output")
+
+    canonical_input = model.canonical_input
+    assert not isinstance(canonical_input, NotAvailable)
+    assert canonical_input.metadata == buff.input.metadata
+
+
+def test_canonical_input_12():
+    # Valued cannection cannot be canonical input
+    model = Model()
+    model += (buff := Buffer())
+    model += Buffer()(input=3 / buff.output)
+
+    canonical_input = model.canonical_input
+    assert not isinstance(canonical_input, NotAvailable)
+    assert canonical_input.metadata == buff.input.metadata
+
+
 def test_canonical_dual_iadd_op():
     model1 = Model()
     model1 += (c1 := Convolution2D(3, 4))