diff --git a/lib/jasmine-node/jasmine-1.3.1.js b/lib/jasmine-node/jasmine-1.3.1.js
index 3cb32a8..0e67725 100644
--- a/lib/jasmine-node/jasmine-1.3.1.js
+++ b/lib/jasmine-node/jasmine-1.3.1.js
@@ -22,6 +22,22 @@ jasmine.unimplementedMethod_ = function() {
  */
 jasmine.undefined = jasmine.___undefined___;
 
+/**
+ * Use <code>jasmine.POSITIVE_INFINITY</code> instead of <code>Infinity</code>, since <code>Infinity</code> is just
+ * a plain old variable and may be redefined by somebody else.
+ *
+ * @private
+ */
+jasmine.POSITIVE_INFINITY = Infinity;
+
+/**
+ * Use <code>jasmine.NEGATIVE_INFINITY</code> instead of <code>-Infinity</code>, since <code>-Infinity</code> is just
+ * a plain old variable and may be redefined by somebody else.
+ *
+ * @private
+ */
+jasmine.NEGATIVE_INFINITY = -Infinity;
+
 /**
  * Show diagnostic messages in the console if set to true
  *
@@ -1414,6 +1430,28 @@ jasmine.Matchers.prototype.toBeNaN = function() {
   return (this.actual !== this.actual);
 };
 
+/**
+ * Matcher that compares the actual to Infinity.
+ */
+jasmine.Matchers.prototype.toBePositiveInfinity = function() {
+  this.message = function() {
+    return [ "Expected " + jasmine.pp(this.actual) + " to be Infinity." ];
+  };
+
+  return (this.actual === jasmine.POSITIVE_INFINITY);
+};
+
+/**
+ * Matcher that compares the actual to -Infinity.
+ */
+jasmine.Matchers.prototype.toBeNegativeInfinity = function() {
+  this.message = function() {
+    return [ "Expected " + jasmine.pp(this.actual) + " to be -Infinity." ];
+  };
+
+  return (this.actual === jasmine.NEGATIVE_INFINITY);
+};
+
 /**
  * Matcher that boolean not-nots the actual.
  */