diff --git a/Cargo.toml b/Cargo.toml
index d0c91a30..facd5a6a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -245,6 +245,7 @@ range_plus_one = "deny"
 redundant_closure_for_method_calls = "deny"
 redundant_else = "deny"
 string_add_assign = "deny"
+string_slice = "deny"
 unchecked_duration_subtraction = "deny"
 uninlined_format_args = "deny"
 unnecessary_box_returns = "deny"