diff --git a/fractal_tasks_core/__init__.py b/fractal_tasks_core/__init__.py
index 4783b7578..64610f0d0 100644
--- a/fractal_tasks_core/__init__.py
+++ b/fractal_tasks_core/__init__.py
@@ -6,6 +6,6 @@
 )
 
 
-__VERSION__ = "0.14.3"
+__VERSION__ = "1.0.0a0"
 __OME_NGFF_VERSION__ = "0.4"
 __FRACTAL_TABLE_VERSION__ = "1"
diff --git a/pyproject.toml b/pyproject.toml
index 4917ffa02..22be9a076 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "fractal-tasks-core"
-version = "0.14.3"
+version = "1.0.0a0"
 description = "Core bioimage-analysis library and tasks of the Fractal analytics platform"
 authors = [
     "Joel Lüthi  <joel.luethi@fmi.ch>",
@@ -89,7 +89,7 @@ source = ["fractal_tasks_core"]
 omit = ["tests/*", "examples/*", "fractal_tasks_core/dev/*", "fractal_tasks_core/tasks/compress_tif.py"]
 
 [tool.bumpver]
-current_version = "0.14.3"
+current_version = "1.0.0a0"
 version_pattern = "MAJOR.MINOR.PATCH[PYTAGNUM]"
 commit_message = "bump version {old_version} -> {new_version}"
 commit = true