1 files changed, 3 insertions, 0 deletions
diff --git a/src/builtins.zig b/src/builtins.zig
index 6688d05f..27a1d36d 100644
--- a/src/builtins.zig
+++ b/src/builtins.zig
@@ -1271,6 +1271,9 @@ pub const Joincol = struct {
         // The keyboard's column joins the one to its right; the last has none.
         const col = c.p.keyboardColumn(c.p.active) orelse return;
         if (col + 1 >= c.p.ncol) return c.p.reportFailure(c.id, "Joincol: no column to the right");
+        // As Newcol is refused: a column that could not give each pane its
+        // tag and 2 rows would leave a layout `size` refuses as it is.
+        if (!layout.joinFits(c.p, col)) return c.p.reportFailure(c.id, "Joincol: no space: the joined column cannot give each pane its tag and 2 rows");
         layout.joinCol(c.p, col);
     }
 };