diff --git a/src/shared/timer-delay.test.ts b/src/shared/timer-delay.test.ts
index 23171a60e99..7f94b33a655 100644
--- a/src/shared/timer-delay.test.ts
+++ b/src/shared/timer-delay.test.ts
@@ -33,17 +33,30 @@ describe('timer delay policy', () => {
     expect(parsePositiveSafeIntegerText(raw)).toBe(expected)
   })
 
-  it.each(['', '0', '-1', '1.5', '.1', '1e-1', '9007199254740991.1', '9007199254740992'])(
-    'rejects inexact or unsafe integer text %s',
-    (raw) => {
-      expect(parsePositiveSafeIntegerText(raw)).toBeNull()
-    }
-  )
+  it.each([
+    '',
+    '0',
+    '-1',
+    '1.5',
+    '.1',
+    '1e-1',
+    '1.0000000000000000001',
+    '+1.0000000000000000001',
+    '9007199254740991.1',
+    '9007199254740992'
+  ])('rejects inexact or unsafe integer text %s', (raw) => {
+    expect(parsePositiveSafeIntegerText(raw)).toBeNull()
+  })
 
+  // Values the CLI's own Number() coercion accepts must parse to the same
+  // budget here, or the caller's timer expires before the CLI's does.
   it.each([
     ['+1000', 1_000],
     ['1000.0', 1_000],
-    ['1e3', 1_000]
+    ['1e3', 1_000],
+    ['1.0000000000000000001', 1],
+    ['+1.0000000000000000001', 1],
+    ['600000.000000000000001', 600_000]
   ])('parses CLI-compatible positive integer text %s', (raw, expected) => {
     expect(parsePositiveSafeIntegerNumericText(raw)).toBe(expected)
   })
diff --git a/src/shared/timer-delay.ts b/src/shared/timer-delay.ts
index 99172b99f45..5f57bb4c10e 100644
--- a/src/shared/timer-delay.ts
+++ b/src/shared/timer-delay.ts
@@ -19,6 +19,12 @@ export function parsePositiveSafeIntegerText(raw: string): number | null {
   return exactValue === BigInt(value) ? value : null
 }
 
+// Why: mirrors the CLI's own `Number()` coercion for generic `--timeout-ms`
+// flags (cli/flags.ts getOptionalPositiveIntegerFlag). Text that coerces to an
+// exact integer — `1000.0`, `600000.000000000000001` — is the budget the CLI
+// will actually wait on, so rejecting it here would leave the caller's timer
+// shorter than the CLI's and cut the request short. Callers that need exact
+// text (orchestration ask) use parsePositiveSafeIntegerText instead.
 export function parsePositiveSafeIntegerNumericText(raw: string): number | null {
   const value = Number(raw)
   return Number.isSafeInteger(value) && value > 0 ? value : null