diff --git a/std/heap.zig b/std/heap.zig
index b654f28a74bb71e03584787efa171349d7eb3867..3f67a9792687663f031a3b35a3c4608e12522aca 100644
--- a/std/heap.zig
+++ b/std/heap.zig
@@ -136,6 +136,14 @@ pub const IncrementingAllocator = struct {
     }
 };
 
+test "c_allocator" {
+    if (builtin.link_libc) {
+        var slice = c_allocator.alloc(u8, 50) %% return;
+        defer c_allocator.free(slice);
+        slice = c_allocator.realloc(u8, slice, 100) %% return;
+    }
+}
+
 test "IncrementingAllocator" {
     const total_bytes = 100 * 1024 * 1024;
     var inc_allocator = %%IncrementingAllocator.init(total_bytes);