diff --git a/src/cliOutput.ts b/src/cliOutput.ts
index e175983e4c..a1a6522d56 100644
--- a/src/cliOutput.ts
+++ b/src/cliOutput.ts
@@ -18,15 +18,25 @@ const VALUED_OUTPUT_FLAGS = new Set([
  */
 export const normalizeCliOutputArguments = (
   arguments_: readonly string[],
-): string[] =>
-  arguments_.flatMap((argument) => {
+): string[] => {
+  const normalized: string[] = [];
+  for (let index = 0; index < arguments_.length; index += 1) {
+    const argument = arguments_[index]!;
+    if (VALUED_OUTPUT_FLAGS.has(argument) && arguments_[index + 1]) {
+      // Incur consumes a nonempty spaced value before looking for more flags.
+      // Its contents belong to that option, even when they look like a flag.
+      normalized.push(argument, arguments_[index + 1]!);
+      index += 1;
+      continue;
+    }
     const separator = argument.indexOf("=");
-    if (separator < 0) return [argument];
     const flag = argument.slice(0, separator);
-    return VALUED_OUTPUT_FLAGS.has(flag)
-      ? [flag, argument.slice(separator + 1)]
-      : [argument];
-  });
+    if (separator >= 0 && VALUED_OUTPUT_FLAGS.has(flag))
+      normalized.push(flag, argument.slice(separator + 1));
+    else normalized.push(argument);
+  }
+  return normalized;
+};
 
 export type CliOutputArgumentValidation =
   | { readonly ok: true }
diff --git a/tests/boundary/cli/cliOutput.test.ts b/tests/boundary/cli/cliOutput.test.ts
index 351a49892c..e26b6d84ef 100644
--- a/tests/boundary/cli/cliOutput.test.ts
+++ b/tests/boundary/cli/cliOutput.test.ts
@@ -60,6 +60,39 @@ describe("CLI output argument boundary", () => {
 });
 
 describe("CLI output flag value forms", () => {
+  it.each(["--filter-output", "--format", "--token-limit", "--token-offset"])(
+    "preserves a flag-shaped spaced value owned by %s",
+    (flag) => {
+      expect(
+        normalizeCliOutputArguments([
+          flag,
+          "--format=json",
+          "providers",
+          "--json",
+        ]),
+      ).toEqual([flag, "--format=json", "providers", "--json"]);
+    },
+  );
+
+  workspaceCliTest(
+    "keeps a flag-shaped filter value equivalent in spaced and equals forms",
+    async ({ cli }) => {
+      for (const filter of [
+        ["--filter-output", "--format=json"],
+        ["--filter-output=--format=json"],
+      ]) {
+        const result = await cli.run({
+          arguments: [...filter, "providers", "--json"],
+          timeoutMs: 10_000,
+        });
+        expect(result.exitCode).toBe(0);
+        expect(JSON.parse(result.stdout)).toEqual({});
+        expect(result.stderr).toBe("");
+      }
+    },
+    CLI_INTEGRATION_TIMEOUT_MS,
+  );
+
   it("splits only the equals forms of valued output flags", () => {
     expect(
       normalizeCliOutputArguments([