diff --git a/demo/app.py b/demo/app.py
index 77417ef1..e38a2297 100644
--- a/demo/app.py
+++ b/demo/app.py
@@ -63,7 +63,7 @@ def main():
     if cam_method is not None:
         cam_extractor = cams.__dict__[cam_method](
             model,
-            target_layer=target_layer if len(target_layer) > 0 else None
+            target_layer=target_layer.split("+") if len(target_layer) > 0 else None
         )
 
     class_choices = [f"{idx + 1} - {class_name}" for idx, class_name in enumerate(LABEL_MAP)]
@@ -91,7 +91,9 @@ def main():
                 else:
                     class_idx = LABEL_MAP.index(class_selection.rpartition(" - ")[-1])
                 # Retrieve the CAM
-                activation_map = cam_extractor(class_idx, out)[0]
+                act_maps = cam_extractor(class_idx, out)
+                # Fuse the CAMs if there are several
+                activation_map = act_maps[0] if len(act_maps) == 1 else cam_extractor.fuse_cams(act_maps)
                 # Plot the raw heatmap
                 fig, ax = plt.subplots()
                 ax.imshow(activation_map.numpy())
diff --git a/test/test_cams_cam.py b/test/test_cams_cam.py
index 4ecf7c48..b0a66a8f 100644
--- a/test/test_cams_cam.py
+++ b/test/test_cams_cam.py
@@ -13,8 +13,8 @@
 def test_base_cam_constructor(mock_img_model):
     model = mobilenet_v2(pretrained=False).eval()
     # Check that multiple target layers is disabled for base CAM
-    with pytest.raises(TypeError):
-        _ = cam.CAM(model, ['classifier.1'])
+    with pytest.raises(ValueError):
+        _ = cam.CAM(model, ['classifier.1', 'classifier.2'])
 
     # FC layer checks
     with pytest.raises(TypeError):
diff --git a/torchcam/cams/cam.py b/torchcam/cams/cam.py
index 1ec228c4..ddb5b758 100644
--- a/torchcam/cams/cam.py
+++ b/torchcam/cams/cam.py
@@ -50,14 +50,14 @@ class CAM(_CAM):
     def __init__(
         self,
         model: nn.Module,
-        target_layer: Optional[Union[nn.Module, str]] = None,
+        target_layer: Optional[Union[Union[nn.Module, str], List[Union[nn.Module, str]]]] = None,
         fc_layer: Optional[Union[nn.Module, str]] = None,
         input_shape: Tuple[int, ...] = (3, 224, 224),
         **kwargs: Any,
     ) -> None:
 
-        if isinstance(target_layer, list):
-            raise TypeError("invalid argument type for `target_layer`")
+        if isinstance(target_layer, list) and len(target_layer) > 1:
+            raise ValueError("base CAM does not support multiple target layers")
 
         super().__init__(model, target_layer, input_shape, **kwargs)
 
@@ -132,7 +132,7 @@ class ScoreCAM(_CAM):
     def __init__(
         self,
         model: nn.Module,
-        target_layer: Optional[str] = None,
+        target_layer: Optional[Union[Union[nn.Module, str], List[Union[nn.Module, str]]]] = None,
         batch_size: int = 32,
         input_shape: Tuple[int, ...] = (3, 224, 224),
         **kwargs: Any,
@@ -257,7 +257,7 @@ class SSCAM(ScoreCAM):
     def __init__(
         self,
         model: nn.Module,
-        target_layer: Optional[str] = None,
+        target_layer: Optional[Union[Union[nn.Module, str], List[Union[nn.Module, str]]]] = None,
         batch_size: int = 32,
         num_samples: int = 35,
         std: float = 2.0,
@@ -346,7 +346,7 @@ class ISCAM(ScoreCAM):
     def __init__(
         self,
         model: nn.Module,
-        target_layer: Optional[str] = None,
+        target_layer: Optional[Union[Union[nn.Module, str], List[Union[nn.Module, str]]]] = None,
         batch_size: int = 32,
         num_samples: int = 10,
         input_shape: Tuple[int, ...] = (3, 224, 224),
diff --git a/torchcam/cams/core.py b/torchcam/cams/core.py
index 896c1049..8e4afc77 100644
--- a/torchcam/cams/core.py
+++ b/torchcam/cams/core.py
@@ -29,7 +29,7 @@ class _CAM:
     def __init__(
         self,
         model: nn.Module,
-        target_layer: Optional[Union[nn.Module, str]] = None,
+        target_layer: Optional[Union[Union[nn.Module, str], List[Union[nn.Module, str]]]] = None,
         input_shape: Tuple[int, ...] = (3, 224, 224),
         enable_hooks: bool = True,
     ) -> None:
diff --git a/torchcam/cams/gradcam.py b/torchcam/cams/gradcam.py
index 22db488e..e8abd493 100644
--- a/torchcam/cams/gradcam.py
+++ b/torchcam/cams/gradcam.py
@@ -27,7 +27,7 @@ class _GradCAM(_CAM):
     def __init__(
         self,
         model: nn.Module,
-        target_layer: Optional[Union[nn.Module, str]] = None,
+        target_layer: Optional[Union[Union[nn.Module, str], List[Union[nn.Module, str]]]] = None,
         input_shape: Tuple[int, ...] = (3, 224, 224),
         **kwargs: Any,
     ) -> None:
@@ -231,7 +231,7 @@ class SmoothGradCAMpp(_GradCAM):
     def __init__(
         self,
         model: nn.Module,
-        target_layer: Optional[Union[nn.Module, str]] = None,
+        target_layer: Optional[Union[Union[nn.Module, str], List[Union[nn.Module, str]]]] = None,
         num_samples: int = 4,
         std: float = 0.3,
         input_shape: Tuple[int, ...] = (3, 224, 224),