diff --git a/arm_compute/core/IArray.h b/arm_compute/core/IArray.h
index 8f84bb1..960e18f 100644
--- a/arm_compute/core/IArray.h
+++ b/arm_compute/core/IArray.h
@@ -30,11 +30,11 @@
 
 namespace arm_compute
 {
-class KeyPoint;
-class Coordinates2D;
-class DetectionWindow;
+struct KeyPoint;
+struct Coordinates2D;
+struct DetectionWindow;
 class Size2D;
-class ROI;
+struct ROI;
 
 /** Array of type T */
 template <class T>