diff --git a/db/db_bench.cc b/db/db_bench.cc
index 8122a1e7bb..8d07f59bcd 100644
--- a/db/db_bench.cc
+++ b/db/db_bench.cc
@@ -219,7 +219,7 @@ static double FLAGS_rate_limit = 0;
 
 // Control maximum bytes of overlaps in grandparent (i.e., level+2) before we
 // stop building a single file in a level->level+1 compaction.
-static int FLAGS_max_grandparent_overlap_factor;
+static int FLAGS_max_grandparent_overlap_factor = 10;
 
 // Run read only benchmarks.
 static bool FLAGS_read_only = false;