diff --git a/libavcodec/rv34.c b/libavcodec/rv34.c
index 7792cad565..294824edb1 100644
--- a/libavcodec/rv34.c
+++ b/libavcodec/rv34.c
@@ -367,7 +367,7 @@ int ff_rv34_get_start_offset(GetBitContext *gb, int mb_size)
 {
     int i;
     for(i = 0; i < 5; i++)
-        if(rv34_mb_max_sizes[i] > mb_size)
+        if(rv34_mb_max_sizes[i] >= mb_size - 1)
             break;
     return rv34_mb_bits_sizes[i];
 }
diff --git a/libavcodec/rv34data.h b/libavcodec/rv34data.h
index e4862a3ba0..95e5572df7 100644
--- a/libavcodec/rv34data.h
+++ b/libavcodec/rv34data.h
@@ -138,7 +138,7 @@ static const uint8_t rv34_dquant_tab[2][32]={
  * maximum number of macroblocks for each of the possible slice offset sizes
  * @todo This is the same as ff_mba_max, maybe use it instead.
  */
-static const uint16_t rv34_mb_max_sizes[6] = { 0x2F, 0x68, 0x18B, 0x62F, 0x18BF, 0x23FF };
+static const uint16_t rv34_mb_max_sizes[6] = { 0x2F, 0x62, 0x18B, 0x62F, 0x18BF, 0x23FF };
 /**
  * bits needed to code the slice offset for the given size
  * @todo This is the same as ff_mba_length, maybe use it instead.