diff --git a/js4g/StackMachine.h b/js4g/StackMachine.h
index 5b77205..8036000 100644
--- a/js4g/StackMachine.h
+++ b/js4g/StackMachine.h
@@ -7,6 +7,7 @@ static_assert( __cplusplus >= 2023'02 );
 #include <iostream>
 
 #include <map>
+#include <unordered_map>
 #include <vector>
 #include <string>
 #include <variant>
@@ -60,7 +61,7 @@ namespace Dillo::Hydrogen::JavaScriptForge	::detail::  StackMachine_m
 
 
 			std::deque< std::string > wordNames;
-			std::map< std::string_view, std::deque< std::string > > words;
+			std::unordered_map< std::string_view, std::deque< std::string > > words;
 
 			// Which side of the current conditional to take.
 			enum ConditionalState { If, Else, Skipped };