diff --git a/src/common/db2.h b/src/common/db2.h
index 223a7de..1c81c8c 100644
--- a/src/common/db2.h
+++ b/src/common/db2.h
@@ -16,6 +16,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #include "common.h"
 #include "mmap.h"