diff --git a/helpers/decrementVar.js b/helpers/decrementVar.js
index f55db63..91f4f82 100644
--- a/helpers/decrementVar.js
+++ b/helpers/decrementVar.js
@@ -13,7 +13,7 @@ const factory = globals => {
             globals.storage.variables = {};
         }
 
-        if (Number.isInteger(globals.storage.variables[key])) {
+        if (globals.storage.variables.hasOwnProperty(key) &&Number.isInteger(globals.storage.variables[key])) {
             // Decrement value if it already exists
             globals.storage.variables[key] -= 1;
         } else {
@@ -26,7 +26,7 @@ const factory = globals => {
         }
 
         // Return current value
-        return globals.storage.variables[key];
+        return globals.storage.variables.hasOwnProperty(key) ? globals.storage.variables[key]: undefined;
     };
 };
 
diff --git a/helpers/dynamicComponent.js b/helpers/dynamicComponent.js
index f403036..15f84c2 100644
--- a/helpers/dynamicComponent.js
+++ b/helpers/dynamicComponent.js
@@ -19,7 +19,7 @@ const factory = globals => {
 
         path = Path.join(path, this['partial']);
 
-        if (globals.handlebars.partials[path]) {
+        if (globals.handlebars.partials[path] && globals.handlebars.partials.hasOwnProperty(path)) {
             return globals.handlebars.partials[path](this);
         }
     };
diff --git a/helpers/getVar.js b/helpers/getVar.js
index f6726d0..048273c 100644
--- a/helpers/getVar.js
+++ b/helpers/getVar.js
@@ -7,7 +7,7 @@ const factory = globals => {
             throw new Error("getVar helper key must be a string");
         }
 
-        return globals.storage.variables ? globals.storage.variables[key] : undefined
+        return globals.storage.variables && globals.storage.variables.hasOwnProperty(key) ? globals.storage.variables[key] : undefined
     };
 };
 
diff --git a/helpers/incrementVar.js b/helpers/incrementVar.js
index a9eef2b..bd953e0 100644
--- a/helpers/incrementVar.js
+++ b/helpers/incrementVar.js
@@ -13,7 +13,7 @@ const factory = globals => {
             globals.storage.variables = {};
         }
 
-        if (Number.isInteger(globals.storage.variables[key])) {
+        if (globals.storage.variables.hasOwnProperty(key) && Number.isInteger(globals.storage.variables[key])) {
             // Increment value if it already exists
             globals.storage.variables[key] += 1;
         } else {
@@ -26,7 +26,7 @@ const factory = globals => {
         }
 
         // Return current value
-        return globals.storage.variables[key];
+        return globals.storage.variables.hasOwnProperty(key) ? globals.storage.variables[key]: undefined;
     };
 };
 
diff --git a/helpers/pluck.js b/helpers/pluck.js
index 80e25f7..68d2ad6 100644
--- a/helpers/pluck.js
+++ b/helpers/pluck.js
@@ -4,7 +4,7 @@ var _ = require('lodash');
 
 const factory = () => {
     return function(collection, path) {
-        return _.map(collection, item => item[path]);
+        return _.map(collection, item => item.hasOwnProperty(path) ? item[path] : undefined);
     };
 };
 
diff --git a/spec/helpers/assignVar-getVar.js b/spec/helpers/assignVar-getVar.js
index 1a9d671..bb75312 100644
--- a/spec/helpers/assignVar-getVar.js
+++ b/spec/helpers/assignVar-getVar.js
@@ -83,4 +83,17 @@ describe('assignVar and getVar helpers', function() {
             done();
         });
     });
+
+    it('should return undefined accessing proto/constructor', function(done) {
+        runTestCases([
+            {
+                input: "{{getVar '__proto__'}}",
+                output: '',
+            },
+            {
+                input: "{{getVar 'constructor'}}",
+                output: '',
+            },
+        ], done);
+    });
 });
diff --git a/spec/helpers/decrementVar.js b/spec/helpers/decrementVar.js
index 727f1f9..9cce47b 100644
--- a/spec/helpers/decrementVar.js
+++ b/spec/helpers/decrementVar.js
@@ -54,4 +54,17 @@ describe('decrementVar helper', function() {
             },
         ], done);
     });
+
+    it('should correctly return data accession object proto/constructor', function(done) {
+        runTestCases([
+            {
+                input: "{{decrementVar '__proto__'}}",
+                output: '',
+            },
+            {
+                input: "{{decrementVar 'constructor'}}",
+                output: '0',
+            },
+        ], done);
+    });
 });
diff --git a/spec/helpers/dynamicComponent.js b/spec/helpers/dynamicComponent.js
index a1a98ce..13a9b5d 100644
--- a/spec/helpers/dynamicComponent.js
+++ b/spec/helpers/dynamicComponent.js
@@ -30,5 +30,18 @@ describe('dynamicComponent helper', function() {
             },
         ], done);
     });
+
+    it('should return undefined when accessing proto/constructor', function(done) {
+        runTestCases([
+            {
+                input: '{{#each fields}}{{dynamicComponent "__proto__"}}{{/each}}',
+                output: '',
+            },
+            {
+                input: '{{#each fields}}{{dynamicComponent "constructor"}}{{/each}}',
+                output: '',
+            },
+        ], done);
+    });
 });
 
diff --git a/spec/helpers/incrementVar.js b/spec/helpers/incrementVar.js
index e67551d..b3c25dc 100644
--- a/spec/helpers/incrementVar.js
+++ b/spec/helpers/incrementVar.js
@@ -54,4 +54,19 @@ describe('incrementVar helper', function() {
             },
         ], done);
     });
+
+
+
+    it('should correctly return data accession object proto/constructor', function(done) {
+        runTestCases([
+            {
+                input: "{{incrementVar '__proto__'}}",
+                output: '',
+            },
+            {
+                input: "{{incrementVar 'constructor'}}",
+                output: '0',
+            },
+        ], done);
+    });
 });
diff --git a/spec/helpers/pluck.js b/spec/helpers/pluck.js
index bbf3e0a..dcc9a4a 100644
--- a/spec/helpers/pluck.js
+++ b/spec/helpers/pluck.js
@@ -26,4 +26,17 @@ describe('pluck helper', function() {
             },
         ], done);
     });
+
+    it('should return undefined when accessing proto/constructor', function(done) {
+        runTestCases([
+            {
+                input: '{{pluck users "__proto__"}}',
+                output: ',',
+            },
+            {
+                input: '{{pluck users "constructor"}}',
+                output: ',',
+            },
+        ], done);
+    });
 });