diff --git a/db/db_bench.cc b/db/db_bench.cc
index 5fed923c7..256c751cf 100644
--- a/db/db_bench.cc
+++ b/db/db_bench.cc
@@ -24,6 +24,7 @@ int main() {
 #include <numaif.h>
 #endif
 
+#include <unistd.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <cstddef>