diff --git a/config/mime.json b/config/mime.json
index ccfffb390..60883ee13 100644
--- a/config/mime.json
+++ b/config/mime.json
@@ -3,7 +3,7 @@
 	"3gp": "video/3gpp",
 	"3gpp": "video/3gpp",
 	"7z": "application/x-7z-compressed",
-	"ai": "application/postscript",
+	"ai": "application/pdf",
 	"aif": "audio/x-aiff",
 	"aiff": "audio/x-aiff",
 	"apk": "application/vnd.android.package-archive",
diff --git a/server/plugin/plg_image_c/image_tiff.c b/server/plugin/plg_image_c/image_tiff.c
index 9131f1c63..5a2e7238e 100644
--- a/server/plugin/plg_image_c/image_tiff.c
+++ b/server/plugin/plg_image_c/image_tiff.c
@@ -4,7 +4,7 @@
 #include <webp/encode.h>
 #include "utils.h"
 
-#define BUF_SIZE 1024 * 128
+#define BUF_SIZE 1024 * 16
 
 int tiff_to_webp(int inputDesc, int outputDesc, int targetSize) {
 #ifdef HAS_DEBUG