diff --git a/types/node/globals.d.ts b/types/node/globals.d.ts
index f7395c7db1..a45f951dd0 100644
--- a/types/node/globals.d.ts
+++ b/types/node/globals.d.ts
@@ -863,7 +863,7 @@ declare namespace NodeJS {
         emitWarning(warning: string | Error, name?: string, ctor?: Function): void;
         env: ProcessEnv;
         exit(code?: number): never;
-        exitCode: number;
+        exitCode?: number;
         getgid(): number;
         setgid(id: number | string): void;
         getuid(): number;
diff --git a/types/node/v10/globals.d.ts b/types/node/v10/globals.d.ts
index f65e76516e..1253df6a96 100644
--- a/types/node/v10/globals.d.ts
+++ b/types/node/v10/globals.d.ts
@@ -716,7 +716,7 @@ declare namespace NodeJS {
         emitWarning(warning: string | Error, name?: string, ctor?: Function): void;
         env: ProcessEnv;
         exit(code?: number): never;
-        exitCode: number;
+        exitCode?: number;
         getgid(): number;
         setgid(id: number | string): void;
         getuid(): number;
diff --git a/types/node/v11/globals.d.ts b/types/node/v11/globals.d.ts
index fffd7f0d49..1146f74ece 100644
--- a/types/node/v11/globals.d.ts
+++ b/types/node/v11/globals.d.ts
@@ -820,7 +820,7 @@ declare namespace NodeJS {
         emitWarning(warning: string | Error, name?: string, ctor?: Function): void;
         env: ProcessEnv;
         exit(code?: number): never;
-        exitCode: number;
+        exitCode?: number;
         getgid(): number;
         setgid(id: number | string): void;
         getuid(): number;
diff --git a/types/node/v9/base.d.ts b/types/node/v9/base.d.ts
index 17f405bfb4..f53cc901e9 100644
--- a/types/node/v9/base.d.ts
+++ b/types/node/v9/base.d.ts
@@ -684,7 +684,7 @@ declare namespace NodeJS {
         emitWarning(warning: string | Error, name?: string, ctor?: Function): void;
         env: ProcessEnv;
         exit(code?: number): never;
-        exitCode: number;
+        exitCode?: number;
         getgid(): number;
         setgid(id: number | string): void;
         getuid(): number;