diff --git a/src/iranges/IRanges.py b/src/iranges/IRanges.py
index 97a5764..7d565a0 100644
--- a/src/iranges/IRanges.py
+++ b/src/iranges/IRanges.py
@@ -950,7 +950,7 @@ def get_elem_counter(idx):
         result = IRanges(result_starts, result_widths)
 
         if with_reverse_map is True:
-            result.set_mcols(BiocFrame({"revmap": result_revmaps}), in_place=True)
+            result._mcols.set_column("revmap", result_revmaps, in_place=True)
 
         return result
 
@@ -1106,7 +1106,7 @@ def disjoin(self, with_reverse_map: bool = False) -> "IRanges":
         result = IRanges(result_starts, result_widths)
 
         if with_reverse_map is True:
-            result.set_mcols(BiocFrame({"revmap": result_revmaps}), in_place=True)
+            result._mcols.set_column("revmap", result_revmaps, in_place=True)
 
         return result