diff --git a/dist/index.js b/dist/index.js
index 33531379..f8abda07 100644
Binary files a/dist/index.js and b/dist/index.js differ
diff --git a/dist/index.js.map b/dist/index.js.map
index e50af36b..9d25c910 100644
Binary files a/dist/index.js.map and b/dist/index.js.map differ
diff --git a/src/model/image-tag.test.ts b/src/model/image-tag.test.ts
index a9241f2e..eb0db0f1 100644
--- a/src/model/image-tag.test.ts
+++ b/src/model/image-tag.test.ts
@@ -2,7 +2,7 @@ import ImageTag from './image-tag';
 
 describe('ImageTag', () => {
   const testImageParameters = {
-    editorVersion: '2099.9.f9f9',
+    editorVersion: '2099.9.9f9',
     targetPlatform: 'Test',
     builderPlatform: '',
     containerRegistryRepository: 'unityci/editor',
@@ -37,6 +37,11 @@ describe('ImageTag', () => {
       ).not.toThrow();
     });
 
+    test.each(['some version', ''])('throws for incorrect version %p', (editorVersion) => {
+      const { targetPlatform } = testImageParameters;
+      expect(() => new ImageTag({ editorVersion, targetPlatform })).toThrow();
+    });
+
     test.each(['nonExisting'])('throws for unsupported target %p', (targetPlatform) => {
       expect(() => new ImageTag({ targetPlatform })).toThrow();
     });
@@ -45,23 +50,23 @@ describe('ImageTag', () => {
   describe('toString', () => {
     it('returns the correct version', () => {
       const image = new ImageTag({
-        editorVersion: '2099.1.1111',
+        editorVersion: '2099.1.1111f1',
         targetPlatform: testImageParameters.targetPlatform,
         containerRegistryRepository: 'unityci/editor',
         containerRegistryImageVersion: '3',
       });
       switch (process.platform) {
         case 'win32':
-          expect(image.toString()).toStrictEqual(`${defaults.image}:windows-2099.1.1111-3`);
+          expect(image.toString()).toStrictEqual(`${defaults.image}:windows-2099.1.1111f1-3`);
           break;
         case 'linux':
-          expect(image.toString()).toStrictEqual(`${defaults.image}:ubuntu-2099.1.1111-3`);
+          expect(image.toString()).toStrictEqual(`${defaults.image}:ubuntu-2099.1.1111f1-3`);
           break;
       }
     });
     it('returns customImage if given', () => {
       const image = new ImageTag({
-        editorVersion: '2099.1.1111',
+        editorVersion: '2099.1.1111f1',
         targetPlatform: testImageParameters.targetPlatform,
         customImage: `${defaults.image}:2099.1.1111@347598437689743986`,
         containerRegistryRepository: 'unityci/editor',
diff --git a/src/model/image-tag.ts b/src/model/image-tag.ts
index 06f68d79..2b9fd910 100644
--- a/src/model/image-tag.ts
+++ b/src/model/image-tag.ts
@@ -20,6 +20,10 @@ class ImageTag {
       providerStrategy,
     } = imageProperties;
 
+    if (!ImageTag.versionPattern.test(editorVersion)) {
+      throw new Error(`Invalid version "${editorVersion}".`);
+    }
+
     // Todo we might as well skip this class for customImage.
     // Either
     this.customImage = customImage;
@@ -37,6 +41,10 @@ class ImageTag {
     this.imageRollingVersion = Number(containerRegistryImageVersion); // Will automatically roll to the latest non-breaking version.
   }
 
+  static get versionPattern(): RegExp {
+    return /^\d+\.\d+\.\d+[a-z]\d+$/;
+  }
+
   static get targetPlatformSuffixes() {
     return {
       generic: '',