diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index f5ee9337b1..9b23f31b69 100644
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -1125,7 +1125,7 @@ static int cbr_bit_allocation(AC3EncodeContext *s)
 
     FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
     for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
-        while (snr_offset + 64 <= 1023 &&
+        while (snr_offset + snr_incr <= 1023 &&
                bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
             snr_offset += snr_incr;
             FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);