diff --git a/modules/camera/CameraHAL.h b/modules/camera/CameraHAL.h
index 00c74e5..74a70a6 100644
--- a/modules/camera/CameraHAL.h
+++ b/modules/camera/CameraHAL.h
@@ -29,7 +29,7 @@
 // camera device.
 class CameraHAL {
     public:
-        CameraHAL(int num_cameras);
+        explicit CameraHAL(int num_cameras);
         ~CameraHAL();
 
         // Camera Module Interface (see <hardware/camera_common.h>)