diff --git a/e2e/__snapshots__/e2e.spec.ts.snap b/e2e/__snapshots__/e2e.spec.ts.snap
index 63a3ef5..f7f8162 100644
--- a/e2e/__snapshots__/e2e.spec.ts.snap
+++ b/e2e/__snapshots__/e2e.spec.ts.snap
@@ -168,23 +168,17 @@ exports[`e2e tests [snapshot] ruleset with unversioned module in source 1`] = `
 "----------------------------------------------------
 modules/unversioned/1.0.0/MODULE.bazel
 ----------------------------------------------------
-module(
-    name = \\"unversioned\\",
-    version = \\"1.0.0\\",
-)
+module(name = \\"unversioned\\", version = \\"1.0.0\\")
+
 ----------------------------------------------------
 modules/unversioned/1.0.0/patches/module_dot_bazel_version.patch
 ----------------------------------------------------
 ===================================================================
 --- a/MODULE.bazel
 +++ b/MODULE.bazel
-@@ -1,4 +1,4 @@
- module(
-     name = \\"unversioned\\",
--    version = \\"0.0.0\\",
-+    version = \\"1.0.0\\",
- )
-\\\\ No newline at end of file
+@@ -1,1 +1,1 @@
+-module(name = \\"unversioned\\")
++module(name = \\"unversioned\\", version = \\"1.0.0\\")
 
 ----------------------------------------------------
 modules/unversioned/1.0.0/presubmit.yml
@@ -204,11 +198,11 @@ bcr_test_module:
 modules/unversioned/1.0.0/source.json
 ----------------------------------------------------
 {
-    \\"integrity\\": \\"sha256-eXQOU+DNwg/Q29tX59jP0+SFLvRHrQf3z+KJVS/gIRk=\\",
+    \\"integrity\\": \\"sha256-X2ZIYATg3qceheFSj/qaTU0SqqW/hFc8UIGkrK3FmZQ=\\",
     \\"strip_prefix\\": \\"unversioned-1.0.0\\",
     \\"url\\": \\"https://github.com/testorg/unversioned/archive/refs/tags/v1.0.0.tar.gz\\",
     \\"patches\\": {
-        \\"module_dot_bazel_version.patch\\": \\"sha256-y0kC8heeH9bQKhrfx2JuX+RK0KyjwHhPac3wBc4Nkg4=\\"
+        \\"module_dot_bazel_version.patch\\": \\"sha256-OoXz9ahBlGjW4IVb4QCmXMZInK7XbFEjCHya3wx8AAk=\\"
     },
     \\"patch_strip\\": 1
 }
diff --git a/e2e/fixtures/unversioned/MODULE.bazel b/e2e/fixtures/unversioned/MODULE.bazel
index 38276ac..e00336e 100644
--- a/e2e/fixtures/unversioned/MODULE.bazel
+++ b/e2e/fixtures/unversioned/MODULE.bazel
@@ -1,4 +1 @@
-module(
-    name = "unversioned",
-    version = "0.0.0",
-)
\ No newline at end of file
+module(name = "unversioned")
diff --git a/src/domain/create-entry.ts b/src/domain/create-entry.ts
index fea6ee0..9d93949 100644
--- a/src/domain/create-entry.ts
+++ b/src/domain/create-entry.ts
@@ -231,7 +231,8 @@ export class CreateEntryService {
   ): void {
     if (moduleFile.version !== version) {
       console.log(
-        "Archived MODULE.bazel version does not match release version. Creating a version patch."
+        `Archived MODULE.bazel version ${moduleFile.version} does not match release version ${version}.`,
+        "Creating a version patch.",
       );
       const patchFileName = "module_dot_bazel_version.patch";
       const existingContent = moduleFile.content;
diff --git a/src/domain/module-file.ts b/src/domain/module-file.ts
index ef66ea7..36817ac 100644
--- a/src/domain/module-file.ts
+++ b/src/domain/module-file.ts
@@ -23,8 +23,8 @@ export class ModuleFile {
 
   public get version(): string {
     const regex = /module\([^)]*?version\s*=\s*"(.+?)"/s;
-    const version = this.moduleContent.match(regex)[1];
-    return version;
+    const match = this.moduleContent.match(regex);
+    return match ? match[1] : "";
   }
 
   public get content(): string {
@@ -32,10 +32,19 @@ export class ModuleFile {
   }
 
   public stampVersion(version: string): void {
-    this.moduleContent = this.moduleContent.replace(
-      /(^.*?module\(.*?version\s*=\s*")[\w.]+(".*$)/s,
-      `$1${version}$2`
-    );
+    if (this.version) {
+      // update the version
+      this.moduleContent = this.moduleContent.replace(
+        /(^.*?module\(.*?version\s*=\s*")[\w.]+(".*$)/s,
+        `$1${version}$2`
+      );
+    } else {
+      // add the version
+      this.moduleContent = this.moduleContent.replace(
+        /(^.*?module\(.*?)\)/s,
+        `$1, version = "${version}")`
+      );
+    }
   }
 
   public save(destPath: string) {