diff --git a/src/main.rs b/src/main.rs
index 009b094..8152b38 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -157,18 +157,40 @@ async fn main() -> Res<()> {
     Ok(())
 }
 
+fn any_parent(
+    tree: &swayipc_async::Node,
+    id: i64,
+    mut test: impl FnMut(&swayipc_async::Node) -> bool,
+) -> bool {
+    tree.find_as_ref(|n| n.focus.contains(&id))
+        .is_some_and(|parent| test(parent) || any_parent(tree, parent.id, test))
+}
+
 async fn autosplit(
     node: &swayipc_async::Node,
     tree: &swayipc_async::Node,
     connection: &mut swayipc_async::Connection,
 ) -> Res<()> {
+    // todo: investigate why we're splitting many layers deep in nested layouts, ie
+    // [tab/stack] -> split
     if node.node_type == swayipc_async::NodeType::Con {
         let (width, height) = (node.window_rect.width, node.window_rect.height);
+
         // we don't want to split zero-sized windows, but containers are also zero-sized
         // - so only skip if size is 0 and we have no children
         if (width == 0 || height == 0) && node.focus.is_empty() {
             return Ok(());
         }
+
+        // don't autosplit if we're in fullscreen
+        if any_parent(&tree, node.id, |n| {
+            (n.node_type == swayipc_async::NodeType::Con
+                || n.node_type == swayipc_async::NodeType::FloatingCon)
+                && n.fullscreen_mode.is_some_and(|m| m != 0)
+        }) {
+            return Ok(());
+        }
+
         if tree
             .find_as_ref(|n| n.focus.contains(&node.id))
             .is_some_and(|parent| {
@@ -178,6 +200,7 @@ async fn autosplit(
         {
             return Ok(());
         }
+
         let config = CONFIG.get().await;
         if !config.autosplit_enabled
             || config.force_tabbed.iter().any(|blocked| {