diff --git a/src/finam/__init__.py b/src/finam/__init__.py
index b9ba0ceffda7f13a2d1f306f00541501a8c04875..5802a5b7d8f9f5fed4dd8f622c5e8cc4f9a19e33 100644
--- a/src/finam/__init__.py
+++ b/src/finam/__init__.py
@@ -79,6 +79,7 @@ Utilities for data and metadata handling.
    :caption: Data tools
 
     Info
+    Mask
     UNITS
 
 Interfaces
@@ -135,6 +136,7 @@ Built-in components, adapters and tool functions.
     tools
 
 """
+
 from . import adapters, data, interfaces, modules, schedule, sdk, tools
 from .data.grid_spec import (
     EsriGrid,
@@ -145,7 +147,7 @@ from .data.grid_spec import (
     UnstructuredPoints,
 )
 from .data.grid_tools import CellType, Location
-from .data.tools import UNITS, Info
+from .data.tools import UNITS, Info, Mask
 from .errors import (
     FinamCircularCouplingError,
     FinamConnectError,
@@ -225,7 +227,7 @@ __all__ += [
     "UnstructuredPoints",
 ]
 __all__ += ["CellType", "Location"]
-__all__ += ["UNITS", "Info"]
+__all__ += ["UNITS", "Info", "Mask"]
 __all__ += [
     "FinamCircularCouplingError",
     "FinamConnectError",
diff --git a/src/finam/data/__init__.py b/src/finam/data/__init__.py
index 67529f570dc7100de3550492d6606ef72a702fe7..f5649355702cb85b6fd1b6e6f9ad8307732de4cd 100644
--- a/src/finam/data/__init__.py
+++ b/src/finam/data/__init__.py
@@ -47,6 +47,7 @@ Data tools
 
     :noindex: UNITS
     :noindex: Info
+    :noindex: Mask
     assert_type
     check
     check_quantified
@@ -92,6 +93,7 @@ from .grid_tools import (
 from .tools import (
     UNITS,
     Info,
+    Mask,
     assert_type,
     check,
     check_data_covers_domain,
@@ -139,6 +141,7 @@ __all__ += [
     "UNITS",
     "FinamDataError",
     "Info",
+    "Mask",
     "assert_type",
     "check",
     "check_quantified",