diff --git a/src/util/TypeMap.hpp b/src/util/TypeMap.hpp
index c41ea8b0..fb469685 100644
--- a/src/util/TypeMap.hpp
+++ b/src/util/TypeMap.hpp
@@ -60,7 +60,6 @@ namespace util {
     private:
         /// The data variable where the data is stored for this map key.
         static std::shared_ptr<Value> data;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-        static std::mutex mutex;             // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
     public:
         /**