diff --git a/std/heap.zig b/std/heap.zig
index 9156dfe936b74de31d1f65c881b389b77012baad..f309a08a8a72a4028f568031a306cda2bb66ea98 100644
--- a/std/heap.zig
+++ b/std/heap.zig
@@ -17,7 +17,8 @@ var c_allocator_state = Allocator {
 };
 
 fn cAlloc(self: &Allocator, n: usize, alignment: u29) ![]u8 {
-    return if (c.aligned_alloc(alignment, n)) |buf|
+    assert(alignment <= @alignOf(c_longdouble));
+    return if (c.malloc(n)) |buf|
         @ptrCast(&u8, buf)[0..n]
     else
         error.OutOfMemory;