diff --git a/slither/utils/erc.py b/slither/utils/erc.py
index 7b40e5b40..4226cdf87 100644
--- a/slither/utils/erc.py
+++ b/slither/utils/erc.py
@@ -29,7 +29,7 @@ ERC20 = [ERC('totalSupply', [], 'uint256', True, True, []),
 
 ERC20_OPTIONAL = [ERC('name', [], 'string', True, False, []),
                   ERC('symbol', [], 'string', True, False, []),
-                  ERC('decimals', [], 'string', True, False, [])]
+                  ERC('decimals', [], 'uint8', True, False, [])]
 
 ERC20 = ERC20 + ERC20_OPTIONAL