diff --git a/std/heap.zig b/std/heap.zig
index a8fc2aa939..2b5316f6c7 100644
--- a/std/heap.zig
+++ b/std/heap.zig
@@ -368,9 +368,9 @@ pub const ArenaAllocator = struct {
         var it = self.buffer_list.first;
         while (it) |node| {
             // this has to occur before the free because the free frees node
-            it = node.next;
-
+            const next_it = node.next;
             self.child_allocator.free(node.data);
+            it = next_it;
         }
     }
 
@@ -764,18 +764,18 @@ test "HeapAllocator" {
     }
 }
 
-//test "ArenaAllocator" {
-//    var direct_allocator = DirectAllocator.init();
-//    defer direct_allocator.deinit();
-//
-//    var arena_allocator = ArenaAllocator.init(&direct_allocator.allocator);
-//    defer arena_allocator.deinit();
-//
-//    try testAllocator(&arena_allocator.allocator);
-//    try testAllocatorAligned(&arena_allocator.allocator, 16);
-//    try testAllocatorLargeAlignment(&arena_allocator.allocator);
-//    try testAllocatorAlignedShrink(&arena_allocator.allocator);
-//}
+test "ArenaAllocator" {
+    var direct_allocator = DirectAllocator.init();
+    defer direct_allocator.deinit();
+
+    var arena_allocator = ArenaAllocator.init(&direct_allocator.allocator);
+    defer arena_allocator.deinit();
+
+    try testAllocator(&arena_allocator.allocator);
+    try testAllocatorAligned(&arena_allocator.allocator, 16);
+    try testAllocatorLargeAlignment(&arena_allocator.allocator);
+    try testAllocatorAlignedShrink(&arena_allocator.allocator);
+}
 
 var test_fixed_buffer_allocator_memory: [80000 * @sizeOf(u64)]u8 = undefined;
 test "FixedBufferAllocator" {
diff --git a/std/std.zig b/std/std.zig
index d8873d6f6a..6ce864fa26 100644
--- a/std/std.zig
+++ b/std/std.zig
@@ -88,7 +88,7 @@ test "std" {
     _ = @import("fmt.zig");
     _ = @import("fs.zig");
     _ = @import("hash.zig");
-    _ = @import("heap.zig"); // TODO commented test
+    _ = @import("heap.zig");
     _ = @import("io.zig");
     //_ = @import("json.zig");
     //_ = @import("lazy_init.zig");