diff --git a/test/filters.js b/test/filters.js
index 80adf457e..592988fbb 100644
--- a/test/filters.js
+++ b/test/filters.js
@@ -26,6 +26,7 @@ describe('filters', function() {
     describe('abs', function() {
         it('should return 3 for -3', () => test('{{ -3 | abs }}', '3'));
         it('should return 2 for arr[0]', () => test('{{ arr[0] | abs }}', '2'));
+        it('should return convert string', () => test('{{ "-3" | abs }}', '3'));
     });
 
     describe('append', function() {
@@ -65,6 +66,7 @@ describe('filters', function() {
         it('should return 2 for 4,2', () => test('{{4 | divided_by: 2}}', '2'));
         it('should return 4 for 16,4', () => test('{{16 | divided_by: 4}}', '4'));
         it('should return 1 for 5,3', () => test('{{5 | divided_by: 3}}', '1'));
+        it('should convert string to number', () => test('{{"5" | divided_by: "3"}}', '1'));
     });
 
     describe('downcase', function() {
@@ -133,7 +135,8 @@ describe('filters', function() {
         it('should return "12" for 16,4', () => test('{{ 16 | minus: 4 }}', '12'));
         it('should return "171.357" for 183.357,12',
             () => test('{{ 183.357 | minus: 12 }}', '171.357'));
-        it('should convert string to number', () => test('{{ "4" | minus: 1 }}', '3'));
+        it('should convert first arg as number', () => test('{{ "4" | minus: 1 }}', '3'));
+        it('should convert both args as number', () => test('{{ "4" | minus: "1" }}', '3'));
     });
 
     describe('modulo', function() {
@@ -141,6 +144,7 @@ describe('filters', function() {
         it('should return "3" for 24,7', () => test('{{ 24 | modulo: 7 }}', '3'));
         it('should return "3.357" for 183.357,12',
             () => test('{{ 183.357 | modulo: 12 }}', '3.357'));
+        it('should convert string', () => test('{{ "24" | modulo: "7" }}', '3'));
     });
 
     it('should support string_with_newlines', function() {
@@ -160,7 +164,8 @@ describe('filters', function() {
         it('should return "20" for 16,4', () => test('{{ 16 | plus: 4 }}', '20'));
         it('should return "195.357" for 183.357,12',
             () => test('{{ 183.357 | plus: 12 }}', '195.357'));
-        it('should convert string to number', () => test('{{ "4" | plus: 2 }}', '6'));
+        it('should convert first arg as number', () => test('{{ "4" | plus: 2 }}', '6'));
+        it('should convert both args as number', () => test('{{ "4" | plus: "2" }}', '6'));
     });
 
     it('should support prepend', function() {
@@ -200,6 +205,7 @@ describe('filters', function() {
         it('should return "3" for 2.7', () => test('{{2.7|round}}', '3'));
         it('should return "183.36" for 183.357,2',
             () => test('{{183.357|round: 2}}', '183.36'));
+        it('should convert string to number', () => test('{{"2.7"|round}}', '3'));
     });
 
     it('should support rstrip', function() {
@@ -266,6 +272,7 @@ describe('filters', function() {
         it('should return "168" for 24,7', () => test('{{ 24 | times: 7 }}', '168'));
         it('should return "2200.284" for 183.357,12',
             () => test('{{ 183.357 | times: 12 }}', '2200.284'));
+        it('should convert string to number', () => test('{{ "24" | times: "7" }}', '168'));
     });
 
     describe('truncate', function() {