diff --git a/scripts/dev-runner.mjs b/scripts/dev-runner.mjs
index 67ffbc2b6937f2e14238bda30a7bf57195592e1a..1c6efcc63d6068221babce6b0509274c7f715a82 100644
--- a/scripts/dev-runner.mjs
+++ b/scripts/dev-runner.mjs
@@ -131,7 +131,7 @@ export function parseDevRunnerArgs(rawArgs) {
       let value = parsedFlag.value;
       if (value === undefined) {
         const next = args[index + 1];
-        if (next === undefined) {
+        if (next === undefined || next === "--" || next.startsWith("-")) {
           throw new Error(`Missing value for --${parsedFlag.name}`);
         }
         value = next;
diff --git a/scripts/dev-runner.test.ts b/scripts/dev-runner.test.ts
index 98dd5bd53be814263870692c7a241bf2378757f0..4501bf7922705fdcc736004848020c1922fb4801 100644
--- a/scripts/dev-runner.test.ts
+++ b/scripts/dev-runner.test.ts
@@ -30,6 +30,12 @@ describe("parseDevRunnerArgs", () => {
   it("throws when a value flag is missing its value", () => {
     expect(() => parseDevRunnerArgs(["--state-dir"])).toThrow("Missing value for --state-dir");
   });
+
+  it("throws when a value flag is followed by another flag token", () => {
+    expect(() => parseDevRunnerArgs(["--state-dir", "--continue"])).toThrow(
+      "Missing value for --state-dir",
+    );
+  });
 });
 
 describe("createDevRunnerEnv", () => {