diff --git a/modeling-cmds/src/def_enum.rs b/modeling-cmds/src/def_enum.rs
index 1b62cfa0..56375ee0 100644
--- a/modeling-cmds/src/def_enum.rs
+++ b/modeling-cmds/src/def_enum.rs
@@ -129,6 +129,11 @@ define_modeling_cmd_enum! {
             /// Should the extrusion create a new object or be part of the existing object.
             #[serde(default)]
             pub extrude_method: ExtrudeMethod,
+            /// Only used if the extrusion is created from a face and extrude_method = Merge
+            /// If true, seams between the extrusion and the original body will be shown. 
+            /// Otherwise, seams resulting from the extrusion will be removed where possible.
+            #[serde(default)]
+            pub merge_coplanar_faces: Option<bool>,
             /// Should this extrude create a solid body or a surface?
             #[serde(default)]
             pub body_type: BodyType,
diff --git a/modeling-session/examples/cube_png.rs b/modeling-session/examples/cube_png.rs
index 3387d788..909d3c0b 100644
--- a/modeling-session/examples/cube_png.rs
+++ b/modeling-session/examples/cube_png.rs
@@ -113,6 +113,7 @@ async fn main() -> Result<()> {
                 faces: None,
                 opposite: Default::default(),
                 extrude_method: Default::default(),
+                merge_coplanar_faces: Default::default(),
                 body_type: Default::default(),
             }
             .into(),
diff --git a/modeling-session/examples/cube_png_batch.rs b/modeling-session/examples/cube_png_batch.rs
index 0af4bc99..088ae075 100644
--- a/modeling-session/examples/cube_png_batch.rs
+++ b/modeling-session/examples/cube_png_batch.rs
@@ -104,6 +104,7 @@ async fn main() -> Result<()> {
             faces: None,
             opposite: Default::default(),
             extrude_method: Default::default(),
+            merge_coplanar_faces: Default::default(),
             body_type: Default::default(),
         }),
         cmd_id: random_id(),
diff --git a/modeling-session/examples/lsystem_png_batch.rs b/modeling-session/examples/lsystem_png_batch.rs
index c45d5910..0389469f 100644
--- a/modeling-session/examples/lsystem_png_batch.rs
+++ b/modeling-session/examples/lsystem_png_batch.rs
@@ -143,6 +143,7 @@ async fn main() -> Result<()> {
             faces: None,
             opposite: Default::default(),
             extrude_method: Default::default(),
+            merge_coplanar_faces: Default::default(),
             body_type: Default::default(),
         }),
         cmd_id: random_id(),