diff --git a/src/devices/IOSDevice.tsx b/src/devices/IOSDevice.tsx
index 5aea7c142..a0d74d630 100644
--- a/src/devices/IOSDevice.tsx
+++ b/src/devices/IOSDevice.tsx
@@ -106,11 +106,11 @@ export default class IOSDevice extends BaseDevice {
         {},
       );
 
-      this.log.on('error', err => {
+      this.log.on('error', (err: Error) => {
         console.error(err);
       });
 
-      this.log.stderr.on('data', data => {
+      this.log.stderr.on('data', (data: Buffer) => {
         console.error(data.toString());
       });
 
@@ -163,7 +163,7 @@ export default class IOSDevice extends BaseDevice {
       '',
     );
 
-    const tag = entry.processImagePath.split('/').pop();
+    const tag = entry.processImagePath.split('/').pop() || '';
 
     return {
       date: new Date(entry.timestamp),
diff --git a/types/JSONStream.d.tsx b/types/JSONStream.d.tsx
new file mode 100644
index 000000000..75b5cf82d
--- /dev/null
+++ b/types/JSONStream.d.tsx
@@ -0,0 +1,47 @@
+/**
+ * Copyright 2018-present Facebook.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @format
+ */
+
+declare module 'JSONStream' {
+  export interface Options {
+    recurse: boolean;
+  }
+
+  export function parse(pattern: any): NodeJS.ReadWriteStream;
+  export function parse(patterns: any[]): NodeJS.ReadWriteStream;
+
+  /**
+   * Create a writable stream.
+   * you may pass in custom open, close, and seperator strings. But, by default,
+   * JSONStream.stringify() will create an array,
+   * (with default options open='[\n', sep='\n,\n', close='\n]\n')
+   */
+  export function stringify(): NodeJS.ReadWriteStream;
+
+  /** If you call JSONStream.stringify(false) the elements will only be seperated by a newline. */
+  export function stringify(
+    newlineOnly: NewlineOnlyIndicator,
+  ): NodeJS.ReadWriteStream;
+  type NewlineOnlyIndicator = false;
+
+  /**
+   * Create a writable stream.
+   * you may pass in custom open, close, and seperator strings. But, by default,
+   * JSONStream.stringify() will create an array,
+   * (with default options open='[\n', sep='\n,\n', close='\n]\n')
+   */
+  export function stringify(
+    open: string,
+    sep: string,
+    close: string,
+  ): NodeJS.ReadWriteStream;
+  export function stringifyObject(): NodeJS.ReadWriteStream;
+  export function stringifyObject(
+    open: string,
+    sep: string,
+    close: string,
+  ): NodeJS.ReadWriteStream;
+}