diff --git a/configure.ac b/configure.ac
index 256aed40b29..8e779f32257 100644
--- a/configure.ac
+++ b/configure.ac
@@ -449,6 +449,9 @@ case $host in
    *openbsd*)
      LEVELDB_TARGET_FLAGS="-DOS_OPENBSD"
      ;;
+   *netbsd*)
+     LEVELDB_TARGET_FLAGS="-DOS_NETBSD"
+     ;;
    *)
      OTHER_OS=`echo ${host_os} | awk '{print toupper($0)}'`
      AC_MSG_WARN([Guessing LevelDB OS as OS_${OTHER_OS}, please check whether this is correct, if not add an entry to configure.ac.])