diff --git a/scripts/dev-runner.mjs b/scripts/dev-runner.mjs
index 60ea70b0963e3fa79cacd14eb6533c25cbbac6ab..8861c1b8378efc2b59f6745f084f437414d58422 100644
--- a/scripts/dev-runner.mjs
+++ b/scripts/dev-runner.mjs
@@ -260,7 +260,13 @@ export async function findFirstAvailableOffset({
 }) {
   for (let candidate = startOffset; ; candidate += 1) {
     const { serverPort, webPort } = portPairForOffset(candidate);
-    if (serverPort > MAX_PORT || webPort > MAX_PORT) {
+    const serverPortOutOfRange = serverPort > MAX_PORT;
+    const webPortOutOfRange = webPort > MAX_PORT;
+    if (
+      (requireServerPort && serverPortOutOfRange) ||
+      (requireWebPort && webPortOutOfRange) ||
+      (!requireServerPort && !requireWebPort && (serverPortOutOfRange || webPortOutOfRange))
+    ) {
       break;
     }
 
diff --git a/scripts/dev-runner.test.ts b/scripts/dev-runner.test.ts
index a9944e1f49f3f795b6f0b5b13334d24f9b9d1a62..eafa3c8c8713ab1ab96c8e08ba2e7f779435b09b 100644
--- a/scripts/dev-runner.test.ts
+++ b/scripts/dev-runner.test.ts
@@ -149,6 +149,17 @@ describe("findFirstAvailableOffset", () => {
 
     expect(offset).toBe(2);
   });
+
+  it("allows offsets where only non-required ports exceed max", async () => {
+    const offset = await findFirstAvailableOffset({
+      startOffset: 59_803,
+      requireServerPort: true,
+      requireWebPort: false,
+      checkPortAvailability: async () => true,
+    });
+
+    expect(offset).toBe(59_803);
+  });
 });
 
 describe("resolveModePortOffsets", () => {