diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index e363388601..e248018184 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -25,7 +25,7 @@ pub use crate::{
 
 pub type Result<T> = ::std::result::Result<T, Box<dyn Error + Send + Sync>>;
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub struct CargoTomlNotFoundError(pub PathBuf);
 
 impl std::fmt::Display for CargoTomlNotFoundError {
@@ -34,12 +34,6 @@ impl std::fmt::Display for CargoTomlNotFoundError {
     }
 }
 
-impl std::fmt::Debug for CargoTomlNotFoundError {
-    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(fmt, "can't find Cargo.toml at {}", self.0.display())
-    }
-}
-
 impl Error for CargoTomlNotFoundError {}
 
 #[derive(Debug, Clone)]