diff --git a/Cargo.toml b/Cargo.toml
index 38d3aecb3..7cb3ff68b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -139,6 +139,7 @@ implicit_clone = "warn"
 needless_for_each = "warn"
 semicolon_if_nothing_returned = "warn"
 uninlined_format_args = "warn"
+useless_conversion = "warn"
 
 # Insta suggests compiling these packages in opt mode for faster testing.
 # See https://docs.rs/insta/latest/insta/#optional-faster-runs.