diff --git a/Tests/UnitTests/Core/Utilities/HelpersTests.cpp b/Tests/UnitTests/Core/Utilities/HelpersTests.cpp
index f6252b82482..aa5e011669d 100644
--- a/Tests/UnitTests/Core/Utilities/HelpersTests.cpp
+++ b/Tests/UnitTests/Core/Utilities/HelpersTests.cpp
@@ -26,6 +26,7 @@
 #include <string>
 #include <tuple>
 #include <utility>
+#include <variant>
 #include <vector>
 
 using namespace Acts::VectorHelpers;