diff --git a/spec/security.js b/spec/security.js
index 00eb1318..1261414b 100644
--- a/spec/security.js
+++ b/spec/security.js
@@ -167,6 +167,7 @@ describe('security issues', function() {
     TestClass.prototype.aMethod = function() {
       return 'returnValue';
     };
+    TestClass.prototype.nested = new TestClass();
 
     beforeEach(function() {
       handlebarsEnv.resetLoggedPropertyAccesses();
@@ -177,17 +178,25 @@ describe('security issues', function() {
     });
 
     describe('control access to prototype methods via "allowedProtoMethods"', function() {
-      checkProtoMethodAccess({});
+      checkProtoMethodAccess('{{aMethod}}', {});
 
       describe('in compat mode', function() {
-        checkProtoMethodAccess({ compat: true });
+        checkProtoMethodAccess('{{aMethod}}', { compat: true });
       });
 
-      function checkProtoMethodAccess(compileOptions) {
+      describe('GH-1858: for nested object', function() {
+        checkProtoMethodAccess('{{nested.aMethod}}', {});
+
+        describe('in compat mode', function() {
+          checkProtoMethodAccess('{{nested.aMethod}}', { compat: true });
+        });
+      });
+
+      function checkProtoMethodAccess(template, compileOptions) {
         it('should be prohibited by default and log a warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aMethod}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .toCompileTo('');
@@ -199,12 +208,12 @@ describe('security issues', function() {
         it('should only log the warning once', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aMethod}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .toCompileTo('');
 
-          expectTemplate('{{aMethod}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .toCompileTo('');
@@ -216,7 +225,7 @@ describe('security issues', function() {
         it('can be allowed, which disables the warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aMethod}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({
@@ -232,7 +241,7 @@ describe('security issues', function() {
         it('can be turned on by default, which disables the warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aMethod}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({
@@ -246,7 +255,7 @@ describe('security issues', function() {
         it('can be turned off by default, which disables the warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aMethod}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({
@@ -258,7 +267,7 @@ describe('security issues', function() {
         });
 
         it('can be turned off, if turned on by default', function() {
-          expectTemplate('{{aMethod}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({
@@ -292,21 +301,33 @@ describe('security issues', function() {
     });
 
     describe('control access to prototype non-methods via "allowedProtoProperties" and "allowProtoPropertiesByDefault', function() {
-      checkProtoPropertyAccess({});
+      checkProtoPropertyAccess('{{aProperty}}', {});
 
       describe('in compat-mode', function() {
-        checkProtoPropertyAccess({ compat: true });
+        checkProtoPropertyAccess('{{aProperty}}', { compat: true });
       });
 
       describe('in strict-mode', function() {
-        checkProtoPropertyAccess({ strict: true });
+        checkProtoPropertyAccess('{{aProperty}}', { strict: true });
       });
 
-      function checkProtoPropertyAccess(compileOptions) {
+      describe('GH-1858: for nested object', function() {
+        checkProtoPropertyAccess('{{nested.aProperty}}', {});
+
+        describe('in compat-mode', function() {
+          checkProtoPropertyAccess('{{nested.aProperty}}', { compat: true });
+        });
+
+        describe('in strict-mode', function() {
+          checkProtoPropertyAccess('{{nested.aProperty}}', { strict: true });
+        });
+      });
+
+      function checkProtoPropertyAccess(template, compileOptions) {
         it('should be prohibited by default and log a warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aProperty}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .toCompileTo('');
@@ -318,7 +339,7 @@ describe('security issues', function() {
         it('can be explicitly prohibited by default, which disables the warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aProperty}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({
@@ -332,7 +353,7 @@ describe('security issues', function() {
         it('can be turned on, which disables the warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aProperty}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({
@@ -348,7 +369,7 @@ describe('security issues', function() {
         it('can be turned on by default, which disables the warning', function() {
           var spy = sinon.spy(console, 'error');
 
-          expectTemplate('{{aProperty}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({
@@ -360,7 +381,7 @@ describe('security issues', function() {
         });
 
         it('can be turned off, if turned on by default', function() {
-          expectTemplate('{{aProperty}}')
+          expectTemplate(template)
             .withInput(new TestClass())
             .withCompileOptions(compileOptions)
             .withRuntimeOptions({