diff --git a/atlas-aapt/external/zlib/src/deflate.c b/atlas-aapt/external/zlib/src/deflate.c
index 696957705..868865cf4 100644
--- a/atlas-aapt/external/zlib/src/deflate.c
+++ b/atlas-aapt/external/zlib/src/deflate.c
@@ -471,7 +471,7 @@ int ZEXPORT deflatePrime (strm, bits, value)
 
     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
     s = strm->state;
-    if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
+    if (s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3))
         return Z_BUF_ERROR;
     do {
         put = Buf_size - s->bi_valid;