diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 9222009fec..dbda25d1d9 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -24,12 +24,10 @@ use hir_expand::{
 };
 use hir_ty::{
     autoderef,
+    diagnostics::{expr::ExprValidator, unsafe_check::UnsafeValidator},
     display::{HirDisplayError, HirFormatter},
-    expr::ExprValidator,
-    method_resolution,
-    unsafe_validation::UnsafeValidator,
-    ApplicationTy, Canonical, GenericPredicate, InEnvironment, Substs, TraitEnvironment, Ty,
-    TyDefId, TypeCtor,
+    method_resolution, ApplicationTy, Canonical, GenericPredicate, InEnvironment, Substs,
+    TraitEnvironment, Ty, TyDefId, TypeCtor,
 };
 use ra_db::{CrateId, Edition, FileId};
 use ra_prof::profile;
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index f74b78b237..bfa543e5b6 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -18,7 +18,7 @@ use hir_def::{
 };
 use hir_expand::{hygiene::Hygiene, name::AsName, HirFileId, InFile};
 use hir_ty::{
-    expr::{record_literal_missing_fields, record_pattern_missing_fields},
+    diagnostics::expr::{record_literal_missing_fields, record_pattern_missing_fields},
     InferenceResult, Substs, Ty,
 };
 use ra_syntax::{
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index 5b0dda634f..07c7729b3a 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -1,4 +1,7 @@
 //! FIXME: write short doc here
+pub mod expr;
+mod match_check;
+pub mod unsafe_check;
 
 use std::any::Any;
 
diff --git a/crates/ra_hir_ty/src/expr.rs b/crates/ra_hir_ty/src/diagnostics/expr.rs
similarity index 99%
rename from crates/ra_hir_ty/src/expr.rs
rename to crates/ra_hir_ty/src/diagnostics/expr.rs
index d44562b227..51c97f8014 100644
--- a/crates/ra_hir_ty/src/expr.rs
+++ b/crates/ra_hir_ty/src/diagnostics/expr.rs
@@ -10,9 +10,9 @@ use rustc_hash::FxHashSet;
 use crate::{
     db::HirDatabase,
     diagnostics::{
+        match_check::{is_useful, MatchCheckCtx, Matrix, PatStack, Usefulness},
         MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, MissingPatFields,
     },
-    match_checking::{is_useful, MatchCheckCtx, Matrix, PatStack, Usefulness},
     utils::variant_data,
     ApplicationTy, InferenceResult, Ty, TypeCtor,
 };
diff --git a/crates/ra_hir_ty/src/match_checking.rs b/crates/ra_hir_ty/src/diagnostics/match_check.rs
similarity index 99%
rename from crates/ra_hir_ty/src/match_checking.rs
rename to crates/ra_hir_ty/src/diagnostics/match_check.rs
index 5495ce284f..722c0e9eea 100644
--- a/crates/ra_hir_ty/src/match_checking.rs
+++ b/crates/ra_hir_ty/src/diagnostics/match_check.rs
@@ -218,15 +218,16 @@
 //!   ```
 use std::sync::Arc;
 
+use hir_def::{
+    adt::VariantData,
+    body::Body,
+    expr::{Expr, Literal, Pat, PatId},
+    AdtId, EnumVariantId, VariantId,
+};
+use ra_arena::Idx;
 use smallvec::{smallvec, SmallVec};
 
-use crate::{
-    db::HirDatabase,
-    expr::{Body, Expr, Literal, Pat, PatId},
-    ApplicationTy, InferenceResult, Ty, TypeCtor,
-};
-use hir_def::{adt::VariantData, AdtId, EnumVariantId, VariantId};
-use ra_arena::Idx;
+use crate::{db::HirDatabase, ApplicationTy, InferenceResult, Ty, TypeCtor};
 
 #[derive(Debug, Clone, Copy)]
 /// Either a pattern from the source code being analyzed, represented as
diff --git a/crates/ra_hir_ty/src/unsafe_validation.rs b/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs
similarity index 100%
rename from crates/ra_hir_ty/src/unsafe_validation.rs
rename to crates/ra_hir_ty/src/diagnostics/unsafe_check.rs
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 2652d200f5..d54568e67a 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -12,15 +12,12 @@ pub mod traits;
 pub mod method_resolution;
 mod op;
 mod lower;
-mod match_checking;
 pub(crate) mod infer;
 pub(crate) mod utils;
 
 pub mod display;
 pub mod db;
 pub mod diagnostics;
-pub mod expr;
-pub mod unsafe_validation;
 
 #[cfg(test)]
 mod tests;
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index dc447955f7..519f43c4e3 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -14,8 +14,8 @@ use stdx::format_to;
 use test_utils::extract_annotations;
 
 use crate::{
-    db::HirDatabase, diagnostics::Diagnostic, expr::ExprValidator,
-    unsafe_validation::UnsafeValidator,
+    db::HirDatabase,
+    diagnostics::{expr::ExprValidator, unsafe_check::UnsafeValidator, Diagnostic},
 };
 
 #[salsa::database(