diff --git a/vapi/zlib.vapi b/vapi/zlib.vapi
index b615f6f..25a2a7d 100644
--- a/vapi/zlib.vapi
+++ b/vapi/zlib.vapi
@@ -45,20 +45,29 @@ namespace ZLib {
 		public const int SYNC;
 		[CCode (cname = "Z_FULL_FLUSH")]
 		public const int FULL;
+		[CCode (cname = "Z_FINISH")]
 		public const int FINISH;
 		public const int BLOCK;
 	}
 
-	[CCode (cprefix = "Z_")]
 	namespace Status {
+		[CCode (cname = "Z_OK")]
 		public const int OK;
+		[CCode (cname = "Z_STREAM_END")]
 		public const int STREAM_END;
+		[CCode (cname = "Z_NEED_DICT")]
 		public const int NEED_DICT;
+		[CCode (cname = "Z_ERRNO")]
 		public const int ERRNO;
+		[CCode (cname = "Z_STREAM_ERROR")]
 		public const int STREAM_ERROR;
+		[CCode (cname = "Z_DATA_ERROR")]
 		public const int DATA_ERROR;
+		[CCode (cname = "Z_MEM_ERROR")]
 		public const int MEM_ERROR;
+		[CCode (cname = "Z_BUF_ERROR")]
 		public const int BUF_ERROR;
+		[CCode (cname = "Z_VERSION_ERROR")]
 		public const int VERSION_ERROR;
 	}
 
@@ -93,17 +102,22 @@ namespace ZLib {
 
 	[CCode (cprefix = "Z_")]
 	namespace Algorithm {
+		[CCode (cname = "Z_DEFLATED")]
 		public const int DEFLATED;
 	}
 
 	[CCode (cname = "z_stream", destroy_function = "deflateEnd")]
 	public struct Stream {
 		[CCode (array_length_cname = "avail_in", array_length_type = "guint")]
-		public uchar[] next_in;
+		public uchar* next_in;
+		public uint avail_in;
+
 		public ulong total_in;
 
 		[CCode (array_length_cname = "avail_out", array_length_type = "guint")]
-		public uchar[] next_out;
+		public uchar* next_out;
+		public uint avail_out;
+
 		public ulong total_out;
 
 		public string? msg;