diff --git a/ethosu/mlw_codec/mlw_encode.h b/ethosu/mlw_codec/mlw_encode.h
index 743603b..68218f3 100644
--- a/ethosu/mlw_codec/mlw_encode.h
+++ b/ethosu/mlw_codec/mlw_encode.h
@@ -47,7 +47,7 @@
     int kernel_width,
     int ifm_depth,
     int* brick_strides,
-    void* inbuf,
+    int16_t* inbuf,
     int ofm_block_depth,
     int is_depthwise,
     int is_partkernel,