diff --git a/packages/cli/src/commands/scale.test.ts b/packages/cli/src/commands/scale.test.ts
index ba208d44..2d689d46 100644
--- a/packages/cli/src/commands/scale.test.ts
+++ b/packages/cli/src/commands/scale.test.ts
@@ -58,6 +58,13 @@ describe('getNextId', () => {
     expect(getNextId(instances)).toBe('inst-0100');
   });
 
+  it('increments ids beyond the safe integer range without collisions', () => {
+    const instances: FleetEntry[] = [
+      { id: 'inst-9007199254740992', provider: 'aws', status: 'running', createdAt: '', hourlyRate: 0.096 },
+    ];
+    expect(getNextId(instances)).toBe('inst-9007199254740993');
+  });
+
   it('ignores ids that do not match the inst- pattern', () => {
     const instances: FleetEntry[] = [
       { id: 'custom-id', provider: 'aws', status: 'running', createdAt: '', hourlyRate: 0.096 },
diff --git a/packages/cli/src/commands/scale.ts b/packages/cli/src/commands/scale.ts
index c57cc9f7..219adb7c 100644
--- a/packages/cli/src/commands/scale.ts
+++ b/packages/cli/src/commands/scale.ts
@@ -116,9 +116,9 @@ export function getNextId(instances: FleetEntry[]): string {
   const nums = instances
     .map((i) => /^inst-(\d+)$/.exec(i.id)?.[1])
     .filter((value): value is string => value !== undefined)
-    .map((value) => Number.parseInt(value, 10));
-  const max = nums.length > 0 ? Math.max(...nums) : 0;
-  return `inst-${String(max + 1).padStart(4, '0')}`;
+    .map((value) => BigInt(value));
+  const max = nums.reduce((highest, value) => value > highest ? value : highest, 0n);
+  return `inst-${String(max + 1n).padStart(4, '0')}`;
 }
 
 export function parsePositiveInteger(value: string): number {