diff --git a/src/test/run-pass/lib-map.rs b/src/test/run-pass/lib-map.rs
index 856a8404a18..bc70e51c9a8 100644
--- a/src/test/run-pass/lib-map.rs
+++ b/src/test/run-pass/lib-map.rs
@@ -13,9 +13,13 @@ fn test_simple() {
     ret u;
   }
 
-  let map.hashfn[uint] hasher = hash;
-  let map.eqfn[uint] eqer = eq;
+  // FIXME we don't really want to bind here but if we don't then the
+  // hashmap's drop glue UMRs when trying to drop these functions, which
+  // it stores internally.
+  let map.hashfn[uint] hasher = bind hash(_);
+  let map.eqfn[uint] eqer = bind eq(_, _);
   let map.hashmap[uint, uint] hm = map.mk_hashmap[uint, uint](hasher, eqer);
+
   hm.insert(10u, 12u);
   hm.insert(11u, 13u);
   hm.insert(12u, 14u);
@@ -24,9 +28,72 @@ fn test_simple() {
   check (hm.get(12u) == 14u);
   check (hm.get(10u) == 12u);
 
+  hm.insert(12u, 14u);
+  check (hm.get(12u) == 14u);
+
+  hm.insert(12u, 12u);
+  check (hm.get(12u) == 12u);
+
   log "*** finished test_simple";
 }
 
+/**
+ * Force map growth and rehashing.
+ */
+fn test_growth() {
+  log "*** starting test_growth";
+
+  let uint map_capacity = 64u;  // Keep in sync with map.mk_hashmap
+
+  fn eq(&uint x, &uint y) -> bool { ret x == y; }
+  fn hash(&uint u) -> uint {
+    // FIXME: can't use std.util.id since we'd be capturing a type param,
+    // and presently we can't close items over type params.
+    ret u;
+  }
+
+  // FIXME: as in test_simple(), don't really want to bind.
+  let map.hashfn[uint] hasher = bind hash(_);
+  let map.eqfn[uint] eqer = bind eq(_, _);
+  let map.hashmap[uint, uint] hm = map.mk_hashmap[uint, uint](hasher, eqer);
+
+  let uint i = 0u;
+  while (i < map_capacity) {
+    hm.insert(i, i * i);
+    log "inserting " + std._uint.to_str(i, 10u)
+      + " -> " + std._uint.to_str(i * i, 10u);
+    i += 1u;
+  }
+
+  log "-----";
+
+  i = 0u;
+  while (i < map_capacity) {
+    log "get(" + std._uint.to_str(i, 10u) + ") = "
+      + std._uint.to_str(hm.get(i), 10u);
+    check (hm.get(i) == i * i);
+    i += 1u;
+  }
+
+  hm.insert(map_capacity, 17u);
+  check (hm.get(map_capacity) == 17u);
+
+  log "-----";
+
+  hm.rehash();
+
+  i = 0u;
+  while (i < map_capacity) {
+    log "get(" + std._uint.to_str(i, 10u) + ") = "
+      + std._uint.to_str(hm.get(i), 10u);
+    check (hm.get(i) == i * i);
+    i += 1u;
+  }
+
+  log "*** finished test_growth";
+}
+
 fn main() {
   test_simple();
+  test_growth();
 }