diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index d5068882..8c16214c 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -1323,7 +1323,7 @@ getJasmineRequireObj().pp = function(j$) {
         this.emitScalar('Date(' + value + ')');
       } else if (value.__Jasmine_been_here_before__) {
         this.emitScalar('<circular reference: ' + (j$.isArray_(value) ? 'Array' : 'Object') + '>');
-      } else if (j$.isArray_(value) || typeof value == 'object') {
+      } else if (j$.isArray_(value) || j$.isA_('Object', value)) {
         value.__Jasmine_been_here_before__ = true;
         if (j$.isArray_(value)) {
           this.emitArray(value);
diff --git a/spec/html/PrettyPrintHtmlSpec.js b/spec/html/PrettyPrintHtmlSpec.js
index 371fe76f..8fd40548 100644
--- a/spec/html/PrettyPrintHtmlSpec.js
+++ b/spec/html/PrettyPrintHtmlSpec.js
@@ -5,4 +5,11 @@ describe("j$.pp (HTML Dependent)", function () {
     expect(j$.pp(sampleNode)).toEqual("HTMLNode");
     expect(j$.pp({foo: sampleNode})).toEqual("{ foo : HTMLNode }");
   });
+
+  it("should print Firefox's wrapped native objects correctly", function() {
+    if(jasmine.getEnv().firefoxVersion) {
+      try { new CustomEvent(); } catch(e) { var err = e; };
+      expect(j$.pp(err)).toMatch(/Exception.*Not enough arguments/);
+    }
+  });
 });
diff --git a/src/core/PrettyPrinter.js b/src/core/PrettyPrinter.js
index 08d2f41c..31e953f5 100644
--- a/src/core/PrettyPrinter.js
+++ b/src/core/PrettyPrinter.js
@@ -29,7 +29,7 @@ getJasmineRequireObj().pp = function(j$) {
         this.emitScalar('Date(' + value + ')');
       } else if (value.__Jasmine_been_here_before__) {
         this.emitScalar('<circular reference: ' + (j$.isArray_(value) ? 'Array' : 'Object') + '>');
-      } else if (j$.isArray_(value) || typeof value == 'object') {
+      } else if (j$.isArray_(value) || j$.isA_('Object', value)) {
         value.__Jasmine_been_here_before__ = true;
         if (j$.isArray_(value)) {
           this.emitArray(value);