diff --git a/build/index.js b/build/index.js
index b38ca66..46041be 100644
--- a/build/index.js
+++ b/build/index.js
@@ -4000,7 +4000,6 @@ async function execCommand(command, args, options = {}, logError = true) {
     }
 }
 async function runAction(opticToken, githubToken, { additionalArgs, standardsFail, eventName, headRef, baseRef, owner, repo, sha, refName, compareFromPush, compareFromPr, }) {
-    var _a;
     const failOnCheckError = standardsFail === "true";
     const valid = verifyInput(opticToken, eventName, owner, repo);
     if (!valid) {
@@ -4021,7 +4020,7 @@ async function runAction(opticToken, githubToken, { additionalArgs, standardsFai
     }
     let from = "";
     if (eventName === "pull_request") {
-        const fromBranch = (_a = compareFromPr !== null && compareFromPr !== void 0 ? compareFromPr : baseRef) !== null && _a !== void 0 ? _a : "";
+        const fromBranch = compareFromPr || baseRef || "";
         const ref = await parseAndEnsureRef(fromBranch);
         if (!ref) {
             core.error(`Unable to fetch ${from}`);
@@ -4030,7 +4029,7 @@ async function runAction(opticToken, githubToken, { additionalArgs, standardsFai
         from = ref;
     }
     else if (eventName === "push") {
-        const fromBranch = compareFromPush !== null && compareFromPush !== void 0 ? compareFromPush : "HEAD~1";
+        const fromBranch = compareFromPush || "HEAD~1";
         const ref = await parseAndEnsureRef(fromBranch);
         if (!ref) {
             core.error(`Unable to fetch ${from}`);
diff --git a/src/action.ts b/src/action.ts
index b3e0b91..1f4a6a4 100644
--- a/src/action.ts
+++ b/src/action.ts
@@ -73,7 +73,7 @@ export async function runAction(
 
   let from = "";
   if (eventName === "pull_request") {
-    const fromBranch = compareFromPr ?? baseRef ?? "";
+    const fromBranch = compareFromPr || baseRef || "";
     const ref = await parseAndEnsureRef(fromBranch);
 
     if (!ref) {
@@ -82,7 +82,7 @@ export async function runAction(
     }
     from = ref;
   } else if (eventName === "push") {
-    const fromBranch = compareFromPush ?? "HEAD~1";
+    const fromBranch = compareFromPush || "HEAD~1";
     const ref = await parseAndEnsureRef(fromBranch);
 
     if (!ref) {