diff --git a/exercises/pangram/example.js b/exercises/pangram/example.js
index c61cfdb9..fca4a7f2 100644
--- a/exercises/pangram/example.js
+++ b/exercises/pangram/example.js
@@ -4,8 +4,9 @@ var notAlpha = /[^a-z]+/gi,
   unique;
 
 var Pangram = function(candidate) {
+  var msg = candidate || '';
   unique = {};
-  cleaned = (candidate.replace(notAlpha, '')).toLowerCase();
+  cleaned = (msg.replace(notAlpha, '')).toLowerCase();
   cleaned.split('').forEach(function (el) {
     unique[el] = true;
   });
diff --git a/exercises/pangram/pangram.spec.js b/exercises/pangram/pangram.spec.js
index d7feee37..7765b39e 100644
--- a/exercises/pangram/pangram.spec.js
+++ b/exercises/pangram/pangram.spec.js
@@ -1,50 +1,61 @@
 var Pangram = require('./pangram');
 
-describe('Pangram()', function()  {
+describe('Tests the Pangram checker.', function()  {
 
-  it('empty sentence', function() {
+  it('can handle an empty sentence', function() {
     var pangram = new Pangram('');
     expect(pangram.isPangram()).toBe(false);
   });
 
-  xit('pangram with only lower case', function()  {
-    var pangram = new Pangram("the quick brown fox jumps over the lazy dog");
-    expect(pangram.isPangram()).toBe(true);
+  xit('handles an undefined message as empty message', function() {
+    var pangram = new Pangram();
+    expect(pangram.isPangram()).toBe(false);
   });
 
-  xit("missing character 'x'", function()  {
-    var pangram = new Pangram("a quick movement of the enemy will jeopardize five gunboats");
-    expect(pangram.isPangram()).toBe(false);
+  xit('recognizes a lower case pangram', function()  {
+    var pangram = new Pangram('thequickbrownfoxjumpsoverthelazydog');
+    expect(pangram.isPangram()).toBe(true);
   });
 
-  xit("another missing character 'x'", function() {
-    var pangram = new Pangram("the quick brown fish jumps over the lazy dog");
+  xit('recognizes a missing character', function()  {
+    // missing 'x'
+    var pangram = new Pangram('aquickmovementoftheenemywilljeopardizefivegunboats');
+    expect(pangram.isPangram()).toBe(false);
+    // missing 'h'
+    var pangram = new Pangram('fiveboxingwizardsjumpquicklyatit');
     expect(pangram.isPangram()).toBe(false);
   });
 
-  xit("pangram with underscores", function() {
-    var pangram = new Pangram("the_quick_brown_fox_jumps_over_the_lazy_dog");
+  xit('recognizes an upper case pangram', function()  {
+    var pangram = new Pangram('THEQUICKBROWNFOXJUMPSOVERTHELAZYDOG');
     expect(pangram.isPangram()).toBe(true);
+    // missing 'G'
+    var pangram = new Pangram('THEQUICKBROWNFOXJUMPSOVERTHELAZYDOLL');
+    expect(pangram.isPangram()).toBe(false);
   });
 
-  xit("pangram with numbers", function() {
-    var pangram = new Pangram("the 1 quick brown fox jumps over the 2 lazy dogs");
+  xit('recognizes a mixed case pangram', function()  {
+    var pangram = new Pangram('ThEFiVebOxInGWiZaRdSJuMpqUiCkLy');
     expect(pangram.isPangram()).toBe(true);
-  });
-
-  xit('missing letters replaced by numbers', function() {
-    var pangram = new Pangram("7h3 qu1ck brown fox jumps ov3r 7h3 lazy dog");
+    // missing 'y'
+    var pangram = new Pangram('ThEFiVebOxInGWiZaRdSJuMpqUiCkL');
     expect(pangram.isPangram()).toBe(false);
   });
 
-  xit('pangram with mixed case and punctuation', function()  {
-    var pangram = new Pangram("\"Five quacking Zephyrs jolt my wax bed.\"");
+  xit('ignores other characters', function() {
+    var pangram = new Pangram('Victor_jagt-zwölf.B0xkämpfer >qu3r< über; den \'großen" Sylter#Deich!');
     expect(pangram.isPangram()).toBe(true);
+    // missing 'd'
+    var pangram = new Pangram('Victor_jagt-zwölf.B0xkämpfer >qu3r< über; einen \'großen" Sylter#Teich!');
+    expect(pangram.isPangram()).toBe(false);
   });
 
-  xit('pangram with non-ascii characters', function()  {
-    var pangram = new Pangram("Victor jagt zwölf Boxkämpfer quer über den großen Sylter Deich.");
+  xit('ignores non-ANSI characters', function()  {
+    var pangram = new Pangram('Few quips galvanized the ① mock 😮 jury box 🗃️.');
     expect(pangram.isPangram()).toBe(true);
+    // substituted 'v' with '℣'
+    var pangram = new Pangram('Few quips gal℣anized the ① mock 😮 jury box 🗃️.');
+    expect(pangram.isPangram()).toBe(false);
   });
 
 });