diff --git a/.changeset/silent-tips-dance.md b/.changeset/silent-tips-dance.md
new file mode 100644
index 0000000..24361f1
--- /dev/null
+++ b/.changeset/silent-tips-dance.md
@@ -0,0 +1,5 @@
+---
+"@changesets/action": patch
+---
+
+Fix the `/version` subaction to not crash on missing `pr-base-branch` input. This input is meant to be optional.
diff --git a/src/index.ts b/src/index.ts
index 247e292..99e5e49 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,13 +1,10 @@
 import fs from "node:fs/promises";
-import path from "node:path";
 import * as core from "@actions/core";
 import { Git } from "./git.ts";
 import { setupOctokit } from "./octokit.ts";
 import readChangesetState from "./readChangesetState.ts";
 import { runPublish, runVersion } from "./run.ts";
-import { fileExists } from "./utils.ts";
-
-const getOptionalInput = (name: string) => core.getInput(name) || undefined;
+import { fileExists, getOptionalInput } from "./utils.ts";
 
 (async () => {
   // to maintain compatibility with workflows created before github-token input was introduced
diff --git a/src/pack/index.ts b/src/pack/index.ts
index e8c5b44..f52f5e8 100644
--- a/src/pack/index.ts
+++ b/src/pack/index.ts
@@ -3,7 +3,11 @@ import os from "node:os";
 import path from "node:path";
 import artifact from "@actions/artifact";
 import * as core from "@actions/core";
-import { downloadArtifact, execChangesetsCli } from "../utils.ts";
+import {
+  downloadArtifact,
+  execChangesetsCli,
+  getOptionalInput,
+} from "../utils.ts";
 
 try {
   await main();
@@ -12,7 +16,7 @@ try {
 }
 
 async function main() {
-  const publishPlanArtifactId = core.getInput("publish-plan-artifact-id");
+  const publishPlanArtifactId = getOptionalInput("publish-plan-artifact-id");
 
   // If the user needs to change the cwd, set `working-directory` in the step instead
   const cwd = process.cwd();
diff --git a/src/pr-comment/index.ts b/src/pr-comment/index.ts
index f280332..b54eb96 100644
--- a/src/pr-comment/index.ts
+++ b/src/pr-comment/index.ts
@@ -1,5 +1,6 @@
 import * as core from "@actions/core";
 import * as github from "@actions/github";
+import { getOptionalInput, getRequiredInput } from "../utils.ts";
 
 type Octokit = ReturnType<typeof github.getOctokit>;
 type CreateCommentParams = NonNullable<
@@ -23,9 +24,9 @@ async function main() {
     );
   }
 
-  const githubToken = core.getInput("github-token", { required: true });
-  const body = core.getInput("body", { required: true });
-  const updateId = core.getInput("update-id");
+  const githubToken = getRequiredInput("github-token");
+  const body = getRequiredInput("body");
+  const updateId = getOptionalInput("update-id");
 
   const commentMarker = updateId ? getCommentMarker(updateId) : null;
   const commentBody = commentMarker ? `${commentMarker}\n\n${body}` : body;
diff --git a/src/publish/index.ts b/src/publish/index.ts
index 6ed399e..d9653c0 100644
--- a/src/publish/index.ts
+++ b/src/publish/index.ts
@@ -4,7 +4,11 @@ import * as core from "@actions/core";
 import { Git } from "../git.ts";
 import { setupOctokit } from "../octokit.ts";
 import { runPublish } from "../run.ts";
-import { downloadArtifact } from "../utils.ts";
+import {
+  downloadArtifact,
+  getOptionalInput,
+  getRequiredInput,
+} from "../utils.ts";
 
 try {
   await main();
@@ -13,9 +17,9 @@ try {
 }
 
 async function main() {
-  const githubToken = core.getInput("github-token", { required: true });
-  const script = core.getInput("script");
-  const packDirArtifactId = core.getInput("pack-dir-artifact-id");
+  const githubToken = getRequiredInput("github-token");
+  const script = getOptionalInput("script");
+  const packDirArtifactId = getOptionalInput("pack-dir-artifact-id");
   const createGithubReleases = core.getBooleanInput("create-github-releases");
 
   // If the user needs to change the cwd, set `working-directory` in the step instead
diff --git a/src/utils.ts b/src/utils.ts
index e21b237..205eb5c 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -2,6 +2,7 @@ import fs from "node:fs/promises";
 import { createRequire } from "node:module";
 import path from "node:path";
 import artifact from "@actions/artifact";
+import * as core from "@actions/core";
 import {
   exec,
   getExecOutput,
@@ -123,6 +124,17 @@ export function fileExists(filePath: string) {
   );
 }
 
+export function getOptionalInput(name: string) {
+  // normalize empty string default return value of `core.getInput` to undefined
+  return core.getInput(name) || undefined;
+}
+
+export function getRequiredInput(name: string) {
+  // it's just a small utility wrapper, mainly introduced for usage parity with our custom `getOptionalInput`
+  // note: `core.getBooleanInput` gets used directly as it already normalizes the return value nicely
+  return core.getInput(name, { required: true });
+}
+
 function resolveChangesetsCli(cwd: string) {
   return require.resolve("@changesets/cli/bin.js", {
     paths: [cwd],
diff --git a/src/version/index.ts b/src/version/index.ts
index 1cf8f55..59f749c 100644
--- a/src/version/index.ts
+++ b/src/version/index.ts
@@ -2,6 +2,7 @@ import * as core from "@actions/core";
 import { Git } from "../git.ts";
 import { setupOctokit } from "../octokit.ts";
 import { runVersion } from "../run.ts";
+import { getOptionalInput, getRequiredInput } from "../utils.ts";
 
 try {
   await main();
@@ -10,13 +11,13 @@ try {
 }
 
 async function main() {
-  const githubToken = core.getInput("github-token", { required: true });
-  const script = core.getInput("script");
-  const commitMessage = core.getInput("commit-message", { required: true });
-  const prTitle = core.getInput("pr-title", { required: true });
-  const prDraft = core.getInput("pr-draft") || undefined;
-  const prBaseBranch = core.getInput("pr-base-branch");
-  const commitMode = core.getInput("commit-mode") || "git-cli";
+  const githubToken = getRequiredInput("github-token");
+  const script = getOptionalInput("script");
+  const commitMessage = getRequiredInput("commit-message");
+  const prTitle = getRequiredInput("pr-title");
+  const prDraft = getOptionalInput("pr-draft");
+  const prBaseBranch = getOptionalInput("pr-base-branch");
+  const commitMode = getOptionalInput("commit-mode") ?? "git-cli";
   const setupGitUser = core.getBooleanInput("setup-git-user");
 
   // Validations