diff --git a/src/blenderbim/blenderbim/bim/import_ifc.py b/src/blenderbim/blenderbim/bim/import_ifc.py
index 4697f297a2..e97ec9ed94 100644
--- a/src/blenderbim/blenderbim/bim/import_ifc.py
+++ b/src/blenderbim/blenderbim/bim/import_ifc.py
@@ -1308,7 +1308,11 @@ class IfcImporter:
             ):
                 return representation.Items[0].MappingTarget
 
-    def create_curve(self, element: ifcopenshell.entity_instance, shape) -> bpy.types.Curve:
+    def create_curve(
+        self,
+        element: ifcopenshell.entity_instance,
+        shape: Union[ifcopenshell.geom.ShapeElementType, ifcopenshell.geom.ShapeType],
+    ) -> bpy.types.Curve:
         if hasattr(shape, "geometry"):
             geometry = shape.geometry
         else:
diff --git a/src/blenderbim/blenderbim/bim/ui.py b/src/blenderbim/blenderbim/bim/ui.py
index 6cdb0cc332..e276164b58 100644
--- a/src/blenderbim/blenderbim/bim/ui.py
+++ b/src/blenderbim/blenderbim/bim/ui.py
@@ -35,15 +35,22 @@ import blenderbim.bim
 import blenderbim.tool as tool
 from blenderbim.bim.helper import IfcHeaderExtractor
 from blenderbim.bim.prop import Attribute
+from typing import Optional
 
 
 class IFCFileSelector:
-    def is_existing_ifc_file(self, filepath=None):
+    filepath: str
+
+    def is_existing_ifc_file(self, filepath: Optional[str] = None) -> bool:
+        """Check if file path exists and if it's an IFC file.
+
+        If `filepath` is not provided, will use filepath property from the current operator.
+        """
         if filepath is None:
             filepath = self.filepath
         return os.path.exists(filepath) and "ifc" in os.path.splitext(filepath)[1].lower()
 
-    def get_filepath(self):
+    def get_filepath(self) -> str:
         """get filepath taking into account relative paths"""
         if self.use_relative_path:
             filepath = os.path.relpath(self.filepath, bpy.path.abspath("//"))