diff --git a/strftime.js b/strftime.js
index c05c3f0..d34ad58 100644
--- a/strftime.js
+++ b/strftime.js
@@ -169,6 +169,9 @@
                         _cachedDate = new Date(_cachedDateTimestamp + getTimestampToUtcOffsetFor(_cachedDate) + _customTimezoneOffset);
                     }
                 }
+                else {
+                  timestamp = _cachedDateTimestamp;
+                }
                 date = _cachedDate;
             }
             else {
diff --git a/test.js b/test.js
index bc60e7b..66db148 100755
--- a/test.js
+++ b/test.js
@@ -195,6 +195,25 @@ assert.formatTZ('%F %r %z', '2011-06-07 11:21:45 AM -0730', '-0730');
 assert.formatTZ('%F %r %:z', '2011-06-07 11:21:45 AM -07:30', '-0730');
 ok('Time zone offset');
 
+/// caching
+(function() {
+    // this test fails when the 2 calls cross a millisecond boundary, so try a number of times
+    var CacheAttempts = 10;
+    var MaxFailures = 1;
+    var failures = 0;
+    for (var i = 0; i < CacheAttempts; ++i) {
+        var expectedMillis = strftime('%L');
+        var millis = strftime('%L');
+        if (expectedMillis != millis) {
+            ++failures;
+        }
+    }
+    if (failures > MaxFailures) {
+        assert.fail('timestamp caching appears to be broken (' + failures + ' failed attempts out of ' + CacheAttempts + ')');
+    }
+}());
+ok('Cached timestamps');
+
 
 /// helpers