diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index 18abd74d..3439c5e1 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -3680,7 +3680,7 @@ getJasmineRequireObj().pp = function(j$) {
   function hasCustomToString(value) {
     // value.toString !== Object.prototype.toString if value has no custom toString but is from another context (e.g.
     // iframe, web worker)
-    return value.toString !== Object.prototype.toString && (value.toString() !== Object.prototype.toString.call(value));
+    return j$.isFunction_(value.toString) && value.toString !== Object.prototype.toString && (value.toString() !== Object.prototype.toString.call(value));
   }
 
   PrettyPrinter.prototype.format = function(value) {
@@ -3708,9 +3708,9 @@ getJasmineRequireObj().pp = function(j$) {
         this.emitScalar('HTMLNode');
       } else if (value instanceof Date) {
         this.emitScalar('Date(' + value + ')');
-      } else if (value.toString && value.toString() == '[object Set]') {
+      } else if (j$.getType_(value) == '[object Set]') {
         this.emitSet(value);
-      } else if (value.toString && value.toString() == '[object Map]') {
+      } else if (j$.getType_(value) == '[object Map]') {
         this.emitMap(value);
       } else if (value.toString && typeof value === 'object' && !j$.isArray_(value) && hasCustomToString(value)) {
         this.emitScalar(value.toString());
diff --git a/spec/core/PrettyPrintSpec.js b/spec/core/PrettyPrintSpec.js
index 905c27ec..e3e64f01 100644
--- a/spec/core/PrettyPrintSpec.js
+++ b/spec/core/PrettyPrintSpec.js
@@ -257,6 +257,14 @@ describe("jasmineUnderTest.pp", function () {
     }
   });
 
+  it("should stringify objects have have a toString that isn't a function", function() {
+    var obj = {
+      toString: "foo"
+    };
+
+    expect(jasmineUnderTest.pp(obj)).toEqual("Object({ toString: 'foo' })");
+  });
+
   it("should stringify objects from anonymous constructors with custom toString", function () {
     var MyAnonymousConstructor = (function() { return function () {}; })();
     MyAnonymousConstructor.toString = function () { return ''; };
diff --git a/src/core/PrettyPrinter.js b/src/core/PrettyPrinter.js
index bd4d8360..5df4166a 100644
--- a/src/core/PrettyPrinter.js
+++ b/src/core/PrettyPrinter.js
@@ -8,7 +8,7 @@ getJasmineRequireObj().pp = function(j$) {
   function hasCustomToString(value) {
     // value.toString !== Object.prototype.toString if value has no custom toString but is from another context (e.g.
     // iframe, web worker)
-    return value.toString !== Object.prototype.toString && (value.toString() !== Object.prototype.toString.call(value));
+    return j$.isFunction_(value.toString) && value.toString !== Object.prototype.toString && (value.toString() !== Object.prototype.toString.call(value));
   }
 
   PrettyPrinter.prototype.format = function(value) {
@@ -36,9 +36,9 @@ getJasmineRequireObj().pp = function(j$) {
         this.emitScalar('HTMLNode');
       } else if (value instanceof Date) {
         this.emitScalar('Date(' + value + ')');
-      } else if (value.toString && value.toString() == '[object Set]') {
+      } else if (j$.getType_(value) == '[object Set]') {
         this.emitSet(value);
-      } else if (value.toString && value.toString() == '[object Map]') {
+      } else if (j$.getType_(value) == '[object Map]') {
         this.emitMap(value);
       } else if (value.toString && typeof value === 'object' && !j$.isArray_(value) && hasCustomToString(value)) {
         this.emitScalar(value.toString());