diff --git a/imagecraft/image_definition.py b/imagecraft/image_definition.py
index c9516997..328c405d 100644
--- a/imagecraft/image_definition.py
+++ b/imagecraft/image_definition.py
@@ -121,7 +121,7 @@ class ImageDefinition(BaseModel):
 
     name: str
     display_name: str
-    revision: str
+    revision: int
     class_: str = Field(alias="class")
     architecture: str
     series: str
@@ -141,7 +141,7 @@ class Config:
     def __init__(  # noqa: PLR0913
         self,
         series: str,
-        revision: str,
+        revision: int,
         architecture: str,
         pocket: str,
         kernel: str | None,
diff --git a/imagecraft/models/project.py b/imagecraft/models/project.py
index a5730389..fc81da7a 100644
--- a/imagecraft/models/project.py
+++ b/imagecraft/models/project.py
@@ -153,6 +153,17 @@ def _validate_package_repositories(
         validate_package_repositories(repositories)
         return repositories
 
+    @validator("version") # pyright: ignore[reportUntypedFunctionDecorator]
+    @classmethod
+    def _validate_version(cls, version: str) -> str:
+        try:
+            int(version)
+        except ValueError as e:
+            raise CraftValidationError(
+                "Invalid version",
+                details="value is not an integer.",
+            ) from e
+        return version
 
     @validator("platforms", pre=True) # pyright: ignore[reportUntypedFunctionDecorator]
     @classmethod
diff --git a/imagecraft/plugins/ubuntu_seed.py b/imagecraft/plugins/ubuntu_seed.py
index 49e46c71..b39a5ac3 100644
--- a/imagecraft/plugins/ubuntu_seed.py
+++ b/imagecraft/plugins/ubuntu_seed.py
@@ -103,7 +103,7 @@ def get_build_commands(self) -> list[str]:
         if branch:
             source_branch = branch
 
-        version = self._part_info.project_info.get_project_var("version", raw_read=True)
+        version = int(self._part_info.project_info.get_project_var("version", raw_read=True))
 
         main_repo = get_main_package_repository(self._part_info.project_info.package_repositories)
 
diff --git a/imagecraft/ubuntu_image.py b/imagecraft/ubuntu_image.py
index b2b0de01..de3fd84a 100644
--- a/imagecraft/ubuntu_image.py
+++ b/imagecraft/ubuntu_image.py
@@ -26,7 +26,7 @@
 
 def ubuntu_image_cmds_build_rootfs(  # noqa: PLR0913
     series: str,
-    version: str,
+    version: int,
     arch: str,
     pocket: str,
     sources: list[str],
diff --git a/tests/conftest.py b/tests/conftest.py
index aab9116e..209a5c04 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -66,7 +66,7 @@ def default_project(extra_project_params):
 
     return Project(
         name=ProjectName("default"),
-        version=VersionStr("1.0"),
+        version=VersionStr("1"),
         summary=SummaryStr("default project"),
         description="default project",
         base="ubuntu@22.04",
diff --git a/tests/unit/models/test_project.py b/tests/unit/models/test_project.py
index 915aa9eb..0af7c6be 100644
--- a/tests/unit/models/test_project.py
+++ b/tests/unit/models/test_project.py
@@ -25,7 +25,7 @@
 
 IMAGECRAFT_YAML_GENERIC = """
 name: ubuntu-server-amd64
-version: "22.04"
+version: 1
 series: jammy
 platforms:
   amd64:
@@ -79,7 +79,7 @@
 
 IMAGECRAFT_YAML_SIMPLE_PLATFORM = """
 name: ubuntu-server-amd64
-version: "22.04"
+version: 1
 series: jammy
 platforms:
   amd64:
@@ -94,7 +94,7 @@
 
 IMAGECRAFT_YAML_MINIMAL_PLATFORM = """
 name: ubuntu-server-amd64
-version: "22.04"
+version: 1
 series: jammy
 platforms:
   amd64:
@@ -107,7 +107,7 @@
 
 IMAGECRAFT_YAML_NO_BUILD_FOR_PLATFORM = """
 name: ubuntu-server-amd64
-version: "22.04"
+version: 1
 series: jammy
 platforms:
   amd64:
@@ -121,7 +121,7 @@
 
 IMAGECRAFT_YAML_SIMPLE_PACKAGE_REPO = """
 name: ubuntu-server-amd64
-version: "22.04"
+version: 1
 series: jammy
 platforms:
   amd64:
@@ -288,3 +288,17 @@ def reload_project_package_repositories(mock_package_repositories, raises):
         mock_package_repositories,
         ProjectValidationError,
     )
+
+
+def test_project_version_invalid(yaml_loaded_data):
+    def reload_project_version(mock_version):
+        yaml_loaded_data["version"] = mock_version
+        with pytest.raises(CraftValidationError) as err:
+            Project.unmarshal(yaml_loaded_data)
+
+        return str(err.value)
+
+    mock_version = ["24.04"]
+    assert "value is not an integer" in reload_project_version(
+        mock_version,
+    )
diff --git a/tests/unit/plugins/test_ubuntu_seed.py b/tests/unit/plugins/test_ubuntu_seed.py
index be19a0ef..9f994940 100644
--- a/tests/unit/plugins/test_ubuntu_seed.py
+++ b/tests/unit/plugins/test_ubuntu_seed.py
@@ -74,7 +74,7 @@ def _ubuntu_seed_plugin(spec, tmp_path):
             plugin_properties=plugin_properties,
         )
         project_vars = {
-            "version": "22.04",
+            "version": "1",
         }
         package_repositories = [
             PackageRepositoryApt.unmarshal(
diff --git a/tests/unit/services/test_lifecycle.py b/tests/unit/services/test_lifecycle.py
index 997464c1..8798b4f2 100644
--- a/tests/unit/services/test_lifecycle.py
+++ b/tests/unit/services/test_lifecycle.py
@@ -45,7 +45,7 @@ def test_lifecycle_args(
         platform="amd64",
         base="ubuntu@22.04",
         project_name="default",
-        project_vars={"version": "1.0"},
+        project_vars={"version": "1"},
         package_repositories=None,
     )
 
@@ -73,7 +73,7 @@ def test_lifecycle_args_no_platform(
         platform=None,
         base="ubuntu@22.04",
         project_name="default",
-        project_vars={"version": "1.0"},
+        project_vars={"version": "1"},
         package_repositories=None,
     )
 
diff --git a/tests/unit/test_application.py b/tests/unit/test_application.py
index 47818d29..f3e4e78e 100644
--- a/tests/unit/test_application.py
+++ b/tests/unit/test_application.py
@@ -16,7 +16,7 @@
 
 IMAGECRAFT_YAML = """
 name: ubuntu-server-amd64
-version: "22.04"
+version: 1
 series: jammy
 platforms:
   amd64:
@@ -59,7 +59,7 @@
 
 IMAGECRAFT_YAML_NO_GADGET = """
 name: ubuntu-server-amd64
-version: "22.04"
+version: 1
 series: jammy
 platforms:
   amd64:
diff --git a/tests/unit/test_ubuntu_image.py b/tests/unit/test_ubuntu_image.py
index 0f72dc9d..8de50c9c 100644
--- a/tests/unit/test_ubuntu_image.py
+++ b/tests/unit/test_ubuntu_image.py
@@ -32,7 +32,7 @@
         (
             ImageDefinition(
                 series="mantic",
-                revision="22.04",
+                revision=1,
                 architecture="amd64",
                 pocket="release",
                 kernel="linux-image-generic",
@@ -69,7 +69,7 @@
             ),
             """name: craft-driver
 display-name: Craft Driver
-revision: '22.04'
+revision: 1
 class: preinstalled
 architecture: amd64
 series: mantic
@@ -114,7 +114,7 @@
         (
             ImageDefinition(
                 series="mantic",
-                revision="22.04",
+                revision=2,
                 architecture="amd64",
                 pocket="proposed",
                 kernel="linux-image-generic",
@@ -129,7 +129,7 @@
             ),
             """name: craft-driver
 display-name: Craft Driver
-revision: '22.04'
+revision: 2
 class: preinstalled
 architecture: amd64
 series: mantic
@@ -158,7 +158,7 @@
         (
             ImageDefinition(
                 series="mantic",
-                revision="22.04",
+                revision=1,
                 architecture="amd64",
                 pocket="proposed",
                 kernel=None,
@@ -173,7 +173,7 @@
             ),
             """name: craft-driver
 display-name: Craft Driver
-revision: '22.04'
+revision: 1
 class: preinstalled
 architecture: amd64
 series: mantic
@@ -200,7 +200,7 @@ def test_ubuntu_image_cmds_build_rootfs(mocker):
 
     assert ubuntu_image_cmds_build_rootfs(
         series="mantic",
-        version="22.04",
+        version=1,
         arch="amd64",
         pocket="proposed",
         sources=["source1", "source2"],