diff --git a/libavformat/utils.c b/libavformat/utils.c
index ae57a6e3e1..caf8df4ebd 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -323,7 +323,7 @@ static const AVOption options[]={
 {"year", "set the year", OFFSET(year), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, E},
 {"analyzeduration", "how many microseconds are analyzed to estimate duration", OFFSET(max_analyze_duration), FF_OPT_TYPE_INT, 3*AV_TIME_BASE, 0, INT_MAX, D},
 {"cryptokey", "decryption key", OFFSET(key), FF_OPT_TYPE_BINARY, 0, 0, 0, D},
-{"indexmem", "max memory used for timestamp index (per stream)", OFFSET(max_index_size), FF_OPT_TYPE_INT, INT_MAX, 0, INT_MAX, D},
+{"indexmem", "max memory used for timestamp index (per stream)", OFFSET(max_index_size), FF_OPT_TYPE_INT, 1<<20, 0, INT_MAX, D},
 {NULL},
 };