diff --git a/runtime/include/types.h b/runtime/include/types.h
index 6dfa980..cc17bf9 100644
--- a/runtime/include/types.h
+++ b/runtime/include/types.h
@@ -36,8 +36,7 @@
 #define round_up_to_page(x) round_up_to_pow2(x, PAGE_SIZE)
 
 /* Type alias's so I don't have to write uint32_t a million times */
-typedef signed char   i8;
-typedef unsigned char u8;
+typedef signed char i8;
 
 /* FIXME: per-module configuration? */
 #define WASM_PAGE_SIZE   (1024 * 64) /* 64KB */