diff --git a/src/backends/reference/workloads/DetectionPostProcess.cpp b/src/backends/reference/workloads/DetectionPostProcess.cpp
index 2108efe..c5ab327 100644
--- a/src/backends/reference/workloads/DetectionPostProcess.cpp
+++ b/src/backends/reference/workloads/DetectionPostProcess.cpp
@@ -6,6 +6,7 @@
 #include "DetectionPostProcess.hpp"
 
 #include <armnn/utility/Assert.hpp>
+#include <armnn/utility/IgnoreUnused.hpp>
 #include <armnn/utility/NumericCast.hpp>
 
 #include <algorithm>