diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4b045765..b175764d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## 0.1.5
+* [[#15](https://github.com/VadimDez/ng2-filter-pipe/issues/15)] - Filter by object key which can be equals null
+
 ## 0.1.4
 * [[#17](https://github.com/VadimDez/ng2-filter-pipe/issues/17)] - Can't filter by getter properties of classes
 
diff --git a/package.json b/package.json
index 78c832eb..2cb3ca2f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ng2-filter-pipe",
-  "version": "0.1.4",
+  "version": "0.1.5",
   "author": "Vadym Yatsyuk <vadym.yatsyuk@gmail.com>",
   "license": "MIT",
   "angular-cli": {},
diff --git a/src/ng2-filter.pipe.ts b/src/ng2-filter.pipe.ts
index c454f34d..317ca468 100644
--- a/src/ng2-filter.pipe.ts
+++ b/src/ng2-filter.pipe.ts
@@ -12,9 +12,11 @@ import { Pipe, Injectable } from '@angular/core';
 export class Ng2FilterPipe {
 
   private filterByString(filter) {
-    filter = filter ? filter.toLowerCase() : filter;
+    if (filter) {
+      filter = filter.toLowerCase();
+    }
     return value => {
-      return !filter || value ? value.toLowerCase().indexOf(filter) !== -1 : false;
+      return !filter || (value ? value.toLowerCase().indexOf(filter) !== -1 : false);
     }
   }
 
@@ -105,4 +107,4 @@ export class Ng2FilterPipe {
 
     return array.filter(this.filterDefault(filter));
   }
-}
+}
\ No newline at end of file