diff --git a/src/array/range.pipe.ts b/src/array/range.pipe.ts
index 7663250..3f270df 100644
--- a/src/array/range.pipe.ts
+++ b/src/array/range.pipe.ts
@@ -1,5 +1,4 @@
 import { Pipe, PipeTransform  } from '@angular/core';
-import { isArray } from '../utils/utils';
 
 @Pipe({
     name: 'range'
diff --git a/src/array/shuffle.pipe.ts b/src/array/shuffle.pipe.ts
index 8325234..8e1158a 100644
--- a/src/array/shuffle.pipe.ts
+++ b/src/array/shuffle.pipe.ts
@@ -1,5 +1,5 @@
 import { Pipe, PipeTransform  } from '@angular/core';
-import { isArray, shuffle } from '../utils/utils';
+import { shuffle } from '../utils/utils';
 
 @Pipe({
     name: 'shuffle'
diff --git a/src/math/degrees.pipe.ts b/src/math/degrees.pipe.ts
index 36279a0..c2854ab 100644
--- a/src/math/degrees.pipe.ts
+++ b/src/math/degrees.pipe.ts
@@ -4,7 +4,7 @@ import { isNumberFinite } from '../utils/utils';
 @Pipe({
     name: 'degrees'
 })
-export class DegreesPipe {
+export class DegreesPipe implements PipeTransform{
     
     
     transform (input: any): any {
diff --git a/src/math/radians.pipe.ts b/src/math/radians.pipe.ts
index d5533ee..464c660 100644
--- a/src/math/radians.pipe.ts
+++ b/src/math/radians.pipe.ts
@@ -1,10 +1,10 @@
 import { Pipe, PipeTransform } from '@angular/core';
-import { isNumberFinite, isInteger } from '../utils/utils';
+import { isNumberFinite } from '../utils/utils';
 
 @Pipe({
     name: 'radians'
 })
-export class RadiansPipe {
+export class RadiansPipe implements PipeTransform {
     
     transform (input: any): any {
         
diff --git a/src/math/random.pipe.ts b/src/math/random.pipe.ts
index ec9747a..7618e6b 100644
--- a/src/math/random.pipe.ts
+++ b/src/math/random.pipe.ts
@@ -4,7 +4,7 @@ import { isNumberFinite } from '../utils/utils';
 @Pipe({
     name: 'random'
 })
-export class RandomPipe {
+export class RandomPipe implements PipeTransform {
     
     transform (input: any, min: number = 0, max: number = 1): any {
         
diff --git a/src/string/encode-uri-component.pipe.ts b/src/string/encode-uri-component.pipe.ts
index e26ce22..157c9fd 100644
--- a/src/string/encode-uri-component.pipe.ts
+++ b/src/string/encode-uri-component.pipe.ts
@@ -4,7 +4,7 @@ import { isString } from '../utils/utils';
 @Pipe({
     name: 'encodeURIComponent'
 })
-export class EncodeURIComponentPipe {
+export class EncodeURIComponentPipe implements PipeTransform {
     
     transform (input: any) {
         
diff --git a/src/string/encode-uri.pipe.ts b/src/string/encode-uri.pipe.ts
index 80e7bb2..065fa1d 100644
--- a/src/string/encode-uri.pipe.ts
+++ b/src/string/encode-uri.pipe.ts
@@ -4,7 +4,7 @@ import { isString } from '../utils/utils';
 @Pipe({
     name: 'encodeURI'
 })
-export class EncodeURIPipe {
+export class EncodeURIPipe implements PipeTransform {
     
     transform (input: any) {
         
diff --git a/src/string/repeat.pipe.ts b/src/string/repeat.pipe.ts
index 8d5d1ba..029be61 100644
--- a/src/string/repeat.pipe.ts
+++ b/src/string/repeat.pipe.ts
@@ -4,7 +4,7 @@ import { isString } from '../utils/utils';
 @Pipe({
     name: 'repeat'
 })
-export class RepeatPipe {
+export class RepeatPipe implements PipeTransform {
     
     transform (input: any, times: number = 1, characters: string = ''): any {
         
diff --git a/tsconfig.json b/tsconfig.json
index 7274e7d..84de7c6 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -8,6 +8,7 @@
         "experimentalDecorators": true,
         "removeComments": false,
         "noImplicitAny": true,
+        "noUnusedLocals": true,        
         "suppressImplicitAnyIndexErrors": false,
         "declaration": true,
         "types": [