diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index 9c6fbc765b..02ec30b285 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -990,8 +990,8 @@ static int dirac_unpack_idwt_params(DiracContext *s)
         /* Codeblock parameters (core syntax only) */
         if (get_bits1(gb)) {
             for (i = 0; i <= s->wavelet_depth; i++) {
-                CHECKEDREAD(s->codeblock[i].width , tmp < 1, "codeblock width invalid\n")
-                CHECKEDREAD(s->codeblock[i].height, tmp < 1, "codeblock height invalid\n")
+                CHECKEDREAD(s->codeblock[i].width , tmp < 1 || tmp > (s->avctx->width >>s->wavelet_depth-i), "codeblock width invalid\n")
+                CHECKEDREAD(s->codeblock[i].height, tmp < 1 || tmp > (s->avctx->height>>s->wavelet_depth-i), "codeblock height invalid\n")
             }
 
             CHECKEDREAD(s->codeblock_mode, tmp > 1, "unknown codeblock mode\n")