diff --git a/trimesh/base.py b/trimesh/base.py
index 5e5ea49f8..ec375a898 100644
--- a/trimesh/base.py
+++ b/trimesh/base.py
@@ -1112,9 +1112,9 @@ def merge_vertices(
         self,
         merge_tex: Optional[bool] = None,
         merge_norm: Optional[bool] = None,
-        digits_vertex: Optional[bool] = None,
-        digits_norm: Optional[bool] = None,
-        digits_uv: Optional[bool] = None,
+        digits_vertex: Optional[int] = None,
+        digits_norm: Optional[int] = None,
+        digits_uv: Optional[int] = None,
     ) -> None:
         """
         Removes duplicate vertices grouped by position and