diff --git a/src/lisp/plat/plat.h b/src/lisp/plat/plat.h
new file mode 100644
index 0000000..227e0d2
--- /dev/null
+++ b/src/lisp/plat/plat.h
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+
+/* Platform specific definitions */
+
+// Must return an address aligned to 8 bytes
+void *malloc_aligned (size_t size);
+void *realloc_aligned (void *addr, size_t size);
+void free_aligned (void *addr);