diff --git a/lib/number_symbols_data.dart b/lib/number_symbols_data.dart
index f389263..843ec3e 100644
--- a/lib/number_symbols_data.dart
+++ b/lib/number_symbols_data.dart
@@ -18,7 +18,7 @@
 
 import "number_symbols.dart";
 
-Map numberFormatSymbols = {
+Map numberFormatSymbols = <String, NumberSymbols>{
   // Number formatting symbols for locale af.
   "af": new NumberSymbols(
       NAME: "af",