diff --git a/docs/types/mapping-types.rst b/docs/types/mapping-types.rst
index 68f963753..454caaf05 100644
--- a/docs/types/mapping-types.rst
+++ b/docs/types/mapping-types.rst
@@ -95,8 +95,8 @@ The example below uses ``_allowances`` to record the amount someone else is allo
 
     contract MappingExample {
 
-        mapping (address => uint256) private _balances;
-        mapping (address => mapping (address => uint256)) private _allowances;
+        mapping(address => uint256) private _balances;
+        mapping(address => mapping(address => uint256)) private _allowances;
 
         event Transfer(address indexed from, address indexed to, uint256 value);
         event Approval(address indexed owner, address indexed spender, uint256 value);