diff --git a/types/cross-spawn/cross-spawn-tests.ts b/types/cross-spawn/cross-spawn-tests.ts
index 6cb36510d8..f6dac4ea72 100644
--- a/types/cross-spawn/cross-spawn-tests.ts
+++ b/types/cross-spawn/cross-spawn-tests.ts
@@ -8,7 +8,7 @@ pw.on('error', (err: Error) => {
     console.log(err);
 });
 
-const r1: Error = spawn.sync('foo').error;
+const r1: Error | undefined = spawn.sync('foo').error;
 const r2: string[] = spawn.sync('foo').output;
 const r3: Buffer = spawn.sync('foo').stdout;
 const r4: Buffer = spawn.sync('foo').stderr;
diff --git a/types/node/child_process.d.ts b/types/node/child_process.d.ts
index 22bf1e5ef4..4e9c882e1b 100644
--- a/types/node/child_process.d.ts
+++ b/types/node/child_process.d.ts
@@ -291,7 +291,7 @@ declare module "child_process" {
         stderr: T;
         status: number;
         signal: string;
-        error: Error;
+        error?: Error;
     }
     function spawnSync(command: string): SpawnSyncReturns<Buffer>;
     function spawnSync(command: string, options?: SpawnSyncOptionsWithStringEncoding): SpawnSyncReturns<string>;
diff --git a/types/node/v10/child_process.d.ts b/types/node/v10/child_process.d.ts
index c8d20b8249..1114247bee 100644
--- a/types/node/v10/child_process.d.ts
+++ b/types/node/v10/child_process.d.ts
@@ -293,7 +293,7 @@ declare module "child_process" {
         stderr: T;
         status: number;
         signal: string;
-        error: Error;
+        error?: Error;
     }
     function spawnSync(command: string): SpawnSyncReturns<Buffer>;
     function spawnSync(command: string, options?: SpawnSyncOptionsWithStringEncoding): SpawnSyncReturns<string>;
diff --git a/types/node/v8/index.d.ts b/types/node/v8/index.d.ts
index 6d5c3d901e..9728ade03f 100644
--- a/types/node/v8/index.d.ts
+++ b/types/node/v8/index.d.ts
@@ -2292,7 +2292,7 @@ declare module "child_process" {
         stderr: T;
         status: number;
         signal: string;
-        error: Error;
+        error?: Error;
     }
     export function spawnSync(command: string): SpawnSyncReturns<Buffer>;
     export function spawnSync(command: string, options?: SpawnSyncOptionsWithStringEncoding): SpawnSyncReturns<string>;