diff --git a/jstests/extent.js b/jstests/extent.js
new file mode 100644
index 00000000000..8fca6998487
--- /dev/null
+++ b/jstests/extent.js
@@ -0,0 +1,11 @@
+t = db.reclaimExtentsTest;
+t.drop();
+
+for ( var i=0; i<50; i++ ) { // enough iterations to break 32 bit.
+    db.createCollection('reclaimExtentsTest', { size : 100000000 });
+    t.insert({x:1});
+    assert( t.count() == 1 );
+    t.drop();
+}
+
+db.dropDatabase();