diff --git a/src/overlay.cpp b/src/overlay.cpp
index f60f554..8df8c8f 100644
--- a/src/overlay.cpp
+++ b/src/overlay.cpp
@@ -41,7 +41,7 @@
 
 constexpr const bool debug = false;
 
-std::regex illegalNameRegex("[^A-Za-z0-9_]");
+const std::regex illegalNameRegex("[^A-Za-z0-9_]");
 
 // helper function to make json types into string
 std::string jsonToString(const nlohmann::json& in)