diff --git a/include/iscsi-private.h b/include/iscsi-private.h
index a60911a..41042a1 100644
--- a/include/iscsi-private.h
+++ b/include/iscsi-private.h
@@ -14,6 +14,8 @@
    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
+#ifndef __iscsi_private_h__
+#define __iscsi_private_h__
 
 #include <stdint.h>
 
@@ -245,3 +247,5 @@ unsigned long crc32c(char *buf, int len);
 
 void iscsi_cbdata_steal_scsi_task(struct scsi_task *task);
 
+#endif /* __iscsi_private_h__ */
+
diff --git a/include/iscsi.h b/include/iscsi.h
index b982c10..0b2b375 100644
--- a/include/iscsi.h
+++ b/include/iscsi.h
@@ -14,6 +14,8 @@
    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
+#ifndef __iscsi_h__
+#define __iscsi_h__
 
 #include <stdint.h>
 
@@ -609,3 +611,4 @@ struct scsi_task *
 iscsi_synchronizecache10_sync(struct iscsi_context *iscsi, int lun, int lba,
 			      int num_blocks, int syncnv, int immed);
 
+#endif /* __iscsi_h__ */
diff --git a/include/scsi-lowlevel.h b/include/scsi-lowlevel.h
index c0f2b4f..7b3dce7 100644
--- a/include/scsi-lowlevel.h
+++ b/include/scsi-lowlevel.h
@@ -14,6 +14,8 @@
    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
+#ifndef __scsi_lowlevel_h__
+#define __scsi_lowlevel_h__
 
 #define SCSI_CDB_MAX_SIZE			16
 
@@ -381,3 +383,6 @@ struct scsi_task *scsi_cdb_write10(uint32_t lba, uint32_t xferlen, int fua, int
 
 struct scsi_task *scsi_cdb_synchronizecache10(int lba, int num_blocks,
 			int syncnv, int immed);
+
+#endif /* __scsi_lowlevel_h__ */
+