diff --git a/ethosu/regor/tosa/tosa_argument_checks.cpp b/ethosu/regor/tosa/tosa_argument_checks.cpp
index b56af12951630d4f486792f7192bf130aefe01af..9ca6b7410e4d70eb7981a8fafa386c94569ba39a 100644
--- a/ethosu/regor/tosa/tosa_argument_checks.cpp
+++ b/ethosu/regor/tosa/tosa_argument_checks.cpp
@@ -26,6 +26,7 @@
 #include "compiler/tensor_properties.hpp"
 
 #include <optional>
+#include <unordered_map>
 #include <unordered_set>
 
 using namespace tosa::validator::checks;