diff --git a/include/types/compression.h b/include/types/compression.h
index da356ad..cf56e45 100644
--- a/include/types/compression.h
+++ b/include/types/compression.h
@@ -51,7 +51,7 @@
 	char *name;
 	int name_len;
 	int (*init)(struct comp_ctx *comp_ctx, int level);
-	int (*add_data)(struct comp_ctx *comp_ctx, const char *in_data, int in_len, char *out_data, int out_len);
+	int (*add_data)(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out);
 	int (*flush)(struct comp_ctx *comp_ctx, struct buffer *out, int flag);
 	int (*reset)(struct comp_ctx *comp_ctx);
 	int (*end)(struct comp_ctx *comp_ctx);