diff --git a/turbojpeg.h b/turbojpeg.h
index 37e492c8..4bc91477 100644
--- a/turbojpeg.h
+++ b/turbojpeg.h
@@ -26,6 +26,9 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#ifndef __TURBOJPEG_H__
+#define __TURBOJPEG_H__
+
 #if defined(_WIN32) && defined(DLLDEFINE)
 #define DLLEXPORT __declspec(dllexport)
 #else
@@ -772,3 +775,5 @@ DLLEXPORT int DLLCALL tjDecompress(tjhandle handle,
 #ifdef __cplusplus
 }
 #endif
+
+#endif