diff --git a/types/serialport/index.d.ts b/types/serialport/index.d.ts
index 0307b323d5..41dba7d66c 100644
--- a/types/serialport/index.d.ts
+++ b/types/serialport/index.d.ts
@@ -21,12 +21,12 @@ declare class SerialPort extends Stream.Duplex {
 	open(callback?: SerialPort.ErrorCallback): void;
 	update(options: SerialPort.UpdateOptions, callback?: SerialPort.ErrorCallback): void;
 
-	write(data: string| number[] | Buffer, callback?: (error: any, bytesWritten: number) => void): boolean;
-	write(buffer: string| number[] | Buffer, encoding?: 'ascii'|'utf8'|'utf16le'|'ucs2'|'base64'|'binary'|'hex', callback?: (error: any, bytesWritten: number) => void): boolean;
+	write(data: string| number[] | Buffer, callback?: (error: Error | null | undefined, bytesWritten: number) => void): boolean;
+	write(buffer: string| number[] | Buffer, encoding?: 'ascii'|'utf8'|'utf16le'|'ucs2'|'base64'|'binary'|'hex', callback?: (error: Error | null | undefined, bytesWritten: number) => void): boolean;
 
 	read(size?: number): string | Buffer | null;
 
-	close(callback?: (error: Error) => void): void;
+	close(callback?: (error?: Error | null) => void): void;
 
 	set(options: SerialPort.SetOptions, callback?: SerialPort.ErrorCallback): void;
 	get(callback?: SerialPort.ModemBitsCallback): void;
@@ -46,9 +46,9 @@ declare class SerialPort extends Stream.Duplex {
 
 declare namespace SerialPort {
 	// Callbacks Type Defs
-	type ErrorCallback = (error: Error) => void;
-	type ModemBitsCallback = (error: Error, status: {cts: boolean, dsr: boolean, dcd: boolean }) => void;
-	type ListCallback = (error: Error, port: any[]) => void;
+	type ErrorCallback = (error?: Error | null) => void;
+	type ModemBitsCallback = (error: Error | null | undefined, status: {cts: boolean, dsr: boolean, dcd: boolean }) => void;
+	type ListCallback = (error: Error | null | undefined, ports: any[]) => void;
 
 	// Options Type Defs
 	interface OpenOptions {
diff --git a/types/serialport/serialport-tests.ts b/types/serialport/serialport-tests.ts
index 476199b506..9ab7ac45a9 100644
--- a/types/serialport/serialport-tests.ts
+++ b/types/serialport/serialport-tests.ts
@@ -8,7 +8,7 @@ function test_basic_connect() {
 
 function test_connect_config() {
     const port1 = new SerialPort('', {
-        }, (error: Error) => {});
+        }, error => {});
 
     const port4 = new SerialPort('', {
             autoOpen: false,
@@ -25,7 +25,13 @@ function test_connect_config() {
                 vmin: 1,
                 vtime: 1
             }
-        }, (error: Error) => {});
+        },
+        error => {
+            if (error !== null) {
+                console.error(error);
+            }
+        }
+    );
 }
 
 function test_open() {
@@ -41,8 +47,8 @@ function test_update() {
 function test_write() {
     const port = new SerialPort('');
 
-    port.write('test', (error: Error) => {});
-    port.write('test', 'utf8', (error: Error) => {});
+    port.write('test', (error?: Error | null) => {});
+    port.write('test', 'utf8', (error?: Error | null) => {});
 }
 
 function test_read() {
@@ -54,13 +60,13 @@ function test_read() {
 function test_close() {
     const port = new SerialPort('');
 
-    port.close((error: Error) => {});
+    port.close((error?: Error | null) => {});
 }
 
 function test_set() {
     const port = new SerialPort('');
 
-    port.set({}, (error: Error) => {});
+    port.set({}, (error?: Error | null) => {});
 }
 
 function test_get() {
@@ -72,13 +78,13 @@ function test_get() {
 function test_flush() {
     const port = new SerialPort('');
 
-    port.flush((error: Error) => {});
+    port.flush((error?: Error | null) => {});
 }
 
 function test_drain() {
     const port = new SerialPort('');
 
-    port.drain((error: Error) => {});
+    port.drain((error?: Error | null) => {});
 }
 
 function test_pause_resume() {
@@ -130,10 +136,10 @@ function test_properties() {
 function test_list_ports_promise() {
     const ports = SerialPort
         .list()
-        .then((ports: any) => {})
+        .then((ports: SerialPort.PortInfo[]) => {})
         .catch((err: Error) => {});
 }
 
 function test_list_ports_callback() {
-    const ports = SerialPort.list((error: Error, port: any[]) => {});
+    const ports = SerialPort.list((error: Error | null | undefined, ports: any[]) => {});
 }
diff --git a/types/serialport/tslint.json b/types/serialport/tslint.json
index 2750cc0197..fcae8d5d63 100644
--- a/types/serialport/tslint.json
+++ b/types/serialport/tslint.json
@@ -1 +1,6 @@
-{ "extends": "dtslint/dt.json" }
\ No newline at end of file
+{
+    "extends": "dtslint/dt.json",
+    "rules": {
+        "strict-type-predicates": true
+    }
+}