diff --git a/masque/__init__.py b/masque/__init__.py
index 38925c1..0f478d6 100644
--- a/masque/__init__.py
+++ b/masque/__init__.py
@@ -106,5 +106,5 @@ from .utils import (
 
 __author__ = 'Jan Petykiewicz'
 
-__version__ = '3.4'
+__version__ = '4.0a1'
 version = __version__       # legacy
diff --git a/pyproject.toml b/pyproject.toml
index 5d7778c..7faebfc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -68,7 +68,7 @@ path = "masque/__init__.py"
 
 [project.optional-dependencies]
 arrow = ["pyarrow", "cffi"]
-oasis = ["fatamorgana~=0.11"]
+oasis = ["fatamorgana>=0.14"]
 dxf = ["ezdxf~=1.4", "pyclipper"]
 svg = ["svgwrite"]
 visualize = ["matplotlib"]