diff --git a/modules/gdscript/editor/gdscript_highlighter.cpp b/modules/gdscript/editor/gdscript_highlighter.cpp
index d70d90c80..fecd9de2d 100644
--- a/modules/gdscript/editor/gdscript_highlighter.cpp
+++ b/modules/gdscript/editor/gdscript_highlighter.cpp
@@ -468,7 +468,7 @@ void GDScriptSyntaxHighlighter::_update_cache() {
 	List<StringName> global_classes;
 	ScriptServer::get_global_class_list(&global_classes);
 	for (List<StringName>::Element *E = global_classes.front(); E; E = E->next()) {
-		keywords[String(E->get())] = usertype_color;
+		keywords[E->get()] = usertype_color;
 	}
 
 	/* Autoloads. */
@@ -503,7 +503,7 @@ void GDScriptSyntaxHighlighter::_update_cache() {
 	List<String> core_types;
 	gdscript->get_core_type_words(&core_types);
 	for (List<String>::Element *E = core_types.front(); E; E = E->next()) {
-		keywords[E->get()] = basetype_color;
+		keywords[StringName(E->get())] = basetype_color;
 	}
 
 	/* Reserved words. */
@@ -513,9 +513,9 @@ void GDScriptSyntaxHighlighter::_update_cache() {
 	gdscript->get_reserved_words(&keyword_list);
 	for (List<String>::Element *E = keyword_list.front(); E; E = E->next()) {
 		if (gdscript->is_control_flow_keyword(E->get())) {
-			keywords[E->get()] = control_flow_keyword_color;
+			keywords[StringName(E->get())] = control_flow_keyword_color;
 		} else {
-			keywords[E->get()] = keyword_color;
+			keywords[StringName(E->get())] = keyword_color;
 		}
 	}
 
diff --git a/modules/gdscript/editor/gdscript_highlighter.h b/modules/gdscript/editor/gdscript_highlighter.h
index a6cfae19a..0adb5356a 100644
--- a/modules/gdscript/editor/gdscript_highlighter.h
+++ b/modules/gdscript/editor/gdscript_highlighter.h
@@ -46,8 +46,8 @@ private:
 	Vector<ColorRegion> color_regions;
 	RBMap<int, int> color_region_cache;
 
-	Dictionary keywords;
-	Dictionary member_keywords;
+	HashMap<StringName, Color> keywords;
+	HashMap<StringName, Color> member_keywords;
 
 	enum Type {
 		NONE,