diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index 0f021fbe..3ed24502 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -1993,7 +1993,7 @@ getJasmineRequireObj().SpyRegistry = function(j$) {
       }
 
       var descriptor = Object.getOwnPropertyDescriptor(obj, methodName);
-      if (!(descriptor.writable || descriptor.set)) {
+      if (descriptor && !(descriptor.writable || descriptor.set)) {
         throw new Error(methodName + ' is not declared writable or has no setter');
       }
 
diff --git a/src/core/SpyRegistry.js b/src/core/SpyRegistry.js
index 08f9c3ff..4c9a90da 100644
--- a/src/core/SpyRegistry.js
+++ b/src/core/SpyRegistry.js
@@ -23,7 +23,7 @@ getJasmineRequireObj().SpyRegistry = function(j$) {
       }
 
       var descriptor = Object.getOwnPropertyDescriptor(obj, methodName);
-      if (!(descriptor.writable || descriptor.set)) {
+      if (descriptor && !(descriptor.writable || descriptor.set)) {
         throw new Error(methodName + ' is not declared writable or has no setter');
       }