diff --git a/tools/create_release.py b/tools/create_release.py
index ecfbd18..6d1163b 100755
--- a/tools/create_release.py
+++ b/tools/create_release.py
@@ -530,9 +530,11 @@ def stage_push(self) -> None:
 
     def has_tarballs(self, version: str) -> bool:
         """Check if there are tarball assets for the given version."""
+        project_name = self.github.repository_name()
+        bare_version = version[1:] if version.startswith("v") else version
         assets = self.github.release_assets(version)
         return all(
-            any(a.name == f"{version}.tar.{ext}" for a in assets)
+            any(a.name == f"{project_name}-{bare_version}.tar.{ext}" for a in assets)
             for ext in ("gz", "xz")
         )
 
diff --git a/tools/create_tarballs.py b/tools/create_tarballs.py
index a681b00..b80fc1a 100755
--- a/tools/create_tarballs.py
+++ b/tools/create_tarballs.py
@@ -42,17 +42,23 @@ def parse_args() -> Config:
     return Config(**vars(args))
 
 
+def _strip_v(tag: str) -> str:
+    """Strip leading 'v' from a tag to get the bare version number."""
+    return tag[1:] if tag.startswith("v") else tag
+
+
 def create_tarballs(project_name: str, tag: str, tmpdir: str) -> None:
     """Create source tarballs with both .gz and .xz for the given tag."""
+    version = _strip_v(tag)
     for prog in ("gzip", "xz"):
-        tarname = f"{os.path.join(tmpdir, tag)}.tar"
+        tarname = f"{os.path.join(tmpdir, project_name)}-{version}.tar"
         print(f"Creating {prog} tarball for {tag}")
         subprocess.run(  # nosec
             [
                 "git",
                 "archive",
                 "--format=tar",
-                f"--prefix={project_name}-{tag}/",
+                f"--prefix={project_name}-{version}/",
                 tag,
                 f"--output={tarname}",
             ],
@@ -64,14 +70,15 @@ def create_tarballs(project_name: str, tag: str, tmpdir: str) -> None:
             subprocess.run([prog, "-f", tarname], check=True)  # nosec
 
 
-def upload_tarballs(tag: str, tmpdir: str) -> None:
+def upload_tarballs(project_name: str, tag: str, tmpdir: str) -> None:
     """Upload the tarballs to GitHub."""
+    version = _strip_v(tag)
     content_type = {
         "gz": "application/gzip",
         "xz": "application/x-xz",
     }
     for ext in ("gz", "xz"):
-        filename = f"{tag}.tar.{ext}"
+        filename = f"{project_name}-{version}.tar.{ext}"
         print(f"Uploading {filename} to GitHub release {tag}")
         with open(os.path.join(tmpdir, filename), "rb") as f:
             github.upload_asset(tag, filename, content_type[ext], f)
@@ -81,7 +88,7 @@ def main(config: Config) -> None:
     if config.upload:
         with tempfile.TemporaryDirectory() as tmpdir:
             create_tarballs(config.project_name, config.tag, tmpdir)
-            upload_tarballs(config.tag, tmpdir)
+            upload_tarballs(config.project_name, config.tag, tmpdir)
     else:
         create_tarballs(config.project_name, config.tag, ".")
 
diff --git a/tools/create_tarballs_test.py b/tools/create_tarballs_test.py
index 09a26d4..dd1853f 100644
--- a/tools/create_tarballs_test.py
+++ b/tools/create_tarballs_test.py
@@ -26,7 +26,7 @@ def test_upload_create(
         mock_tmp.return_value.__enter__.return_value = "/tmp/dir"  # nosec
         main(self.config)
         mock_create.assert_called_once_with("ci-tools", "v1.0.0", "/tmp/dir")  # nosec
-        mock_upload.assert_called_once_with("v1.0.0", "/tmp/dir")  # nosec
+        mock_upload.assert_called_once_with("ci-tools", "v1.0.0", "/tmp/dir")  # nosec
 
     @patch("subprocess.run")
     @patch("create_tarballs.os.path.join")
@@ -49,14 +49,14 @@ def test_create_tarballs_logic(
                     "git",
                     "archive",
                     "--format=tar",
-                    "--prefix=ci-tools-v1.0.0/",
+                    "--prefix=ci-tools-1.0.0/",
                     "v1.0.0",
-                    "--output=/tmp/dir/v1.0.0.tar",  # nosec
+                    "--output=/tmp/dir/ci-tools-1.0.0.tar",  # nosec
                 ],
                 check=True,
             )
             mock_run.assert_any_call(
-                ["gzip", "-nf", "/tmp/dir/v1.0.0.tar"], check=True  # nosec
+                ["gzip", "-nf", "/tmp/dir/ci-tools-1.0.0.tar"], check=True  # nosec
             )