diff --git a/lib/zlib/tf_gunzip.c b/lib/zlib/tf_gunzip.c
index f07c380..574d871 100644
--- a/lib/zlib/tf_gunzip.c
+++ b/lib/zlib/tf_gunzip.c
@@ -89,8 +89,8 @@
 		ret = (zret == Z_MEM_ERROR) ? -ENOMEM : -EIO;
 	}
 
-	VERBOSE("zlib: %d byte input\n", stream.total_in);
-	VERBOSE("zlib: %d byte output\n", stream.total_out);
+	VERBOSE("zlib: %lu byte input\n", stream.total_in);
+	VERBOSE("zlib: %lu byte output\n", stream.total_out);
 
 	*in_buf = (uintptr_t)stream.next_in;
 	*out_buf = (uintptr_t)stream.next_out;