diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index 6d917bb1b6fd..325f1d7b62f3 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -6,7 +6,7 @@ use std::sync::Arc;
 use ra_arena::{RawId, Arena, impl_arena_id};
 use ra_syntax::{
     TreeArc,
-    ast::{self, NameOwner, StructFlavor}
+    ast::{self, NameOwner, StructFlavor, TypeAscriptionOwner}
 };
 
 use crate::{
@@ -164,7 +164,7 @@ impl VariantData {
                     .fields()
                     .map(|fd| StructFieldData {
                         name: fd.name().map(|n| n.as_name()).unwrap_or_else(Name::missing),
-                        type_ref: TypeRef::from_ast_opt(fd.type_ref()),
+                        type_ref: TypeRef::from_ast_opt(fd.ascribed_type()),
                     })
                     .collect();
                 VariantDataInner::Struct(fields)
diff --git a/crates/ra_hir/src/code_model_impl/function.rs b/crates/ra_hir/src/code_model_impl/function.rs
index c401528c6080..c1654b069b91 100644
--- a/crates/ra_hir/src/code_model_impl/function.rs
+++ b/crates/ra_hir/src/code_model_impl/function.rs
@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use ra_syntax::ast::{self, NameOwner};
+use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 
 use crate::{
     Name, AsName, Function, FnSignature,
@@ -19,7 +19,7 @@ impl FnSignature {
         let mut has_self_param = false;
         if let Some(param_list) = node.param_list() {
             if let Some(self_param) = param_list.self_param() {
-                let self_type = if let Some(type_ref) = self_param.type_ref() {
+                let self_type = if let Some(type_ref) = self_param.ascribed_type() {
                     TypeRef::from_ast(type_ref)
                 } else {
                     let self_type = TypeRef::Path(Name::self_type().into());
@@ -37,7 +37,7 @@ impl FnSignature {
                 has_self_param = true;
             }
             for param in param_list.params() {
-                let type_ref = TypeRef::from_ast_opt(param.type_ref());
+                let type_ref = TypeRef::from_ast_opt(param.ascribed_type());
                 params.push(type_ref);
             }
         }
diff --git a/crates/ra_hir/src/code_model_impl/konst.rs b/crates/ra_hir/src/code_model_impl/konst.rs
index ecf4c8122f4c..8b861a81f7be 100644
--- a/crates/ra_hir/src/code_model_impl/konst.rs
+++ b/crates/ra_hir/src/code_model_impl/konst.rs
@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use ra_syntax::ast::{self, NameOwner};
+use ra_syntax::ast::{NameOwner, TypeAscriptionOwner};
 
 use crate::{
     Name, AsName, Const, ConstSignature, Static,
@@ -8,12 +8,9 @@ use crate::{
     PersistentHirDatabase,
 };
 
-fn const_signature_for<N: NameOwner>(
-    node: &N,
-    type_ref: Option<&ast::TypeRef>,
-) -> Arc<ConstSignature> {
+fn const_signature_for<N: NameOwner + TypeAscriptionOwner>(node: &N) -> Arc<ConstSignature> {
     let name = node.name().map(|n| n.as_name()).unwrap_or_else(Name::missing);
-    let type_ref = TypeRef::from_ast_opt(type_ref);
+    let type_ref = TypeRef::from_ast_opt(node.ascribed_type());
     let sig = ConstSignature { name, type_ref };
     Arc::new(sig)
 }
@@ -24,7 +21,7 @@ impl ConstSignature {
         konst: Const,
     ) -> Arc<ConstSignature> {
         let (_, node) = konst.source(db);
-        const_signature_for(&*node, node.type_ref())
+        const_signature_for(&*node)
     }
 
     pub(crate) fn static_signature_query(
@@ -32,6 +29,6 @@ impl ConstSignature {
         konst: Static,
     ) -> Arc<ConstSignature> {
         let (_, node) = konst.source(db);
-        const_signature_for(&*node, node.type_ref())
+        const_signature_for(&*node)
     }
 }
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index e9db8282f5a0..aa39d28ed986 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -6,7 +6,7 @@ use rustc_hash::FxHashMap;
 use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
 use ra_syntax::{
     SyntaxNodePtr, AstNode,
-    ast::{self, LoopBodyOwner, ArgListOwner, NameOwner, LiteralFlavor}
+    ast::{self, LoopBodyOwner, ArgListOwner, NameOwner, LiteralFlavor, TypeAscriptionOwner}
 };
 
 use crate::{
@@ -709,7 +709,7 @@ impl ExprCollector {
                 if let Some(pl) = e.param_list() {
                     for param in pl.params() {
                         let pat = self.collect_pat_opt(param.pat());
-                        let type_ref = param.type_ref().map(TypeRef::from_ast);
+                        let type_ref = param.ascribed_type().map(TypeRef::from_ast);
                         args.push(pat);
                         arg_types.push(type_ref);
                     }
@@ -790,7 +790,7 @@ impl ExprCollector {
             .map(|s| match s.kind() {
                 ast::StmtKind::LetStmt(stmt) => {
                     let pat = self.collect_pat_opt(stmt.pat());
-                    let type_ref = stmt.type_ref().map(TypeRef::from_ast);
+                    let type_ref = stmt.ascribed_type().map(TypeRef::from_ast);
                     let initializer = stmt.initializer().map(|e| self.collect_expr(e));
                     Statement::Let { pat, type_ref, initializer }
                 }
diff --git a/crates/ra_hir/src/type_ref.rs b/crates/ra_hir/src/type_ref.rs
index ee8b7376aba6..8aa807648211 100644
--- a/crates/ra_hir/src/type_ref.rs
+++ b/crates/ra_hir/src/type_ref.rs
@@ -1,7 +1,7 @@
 //! HIR for references to types. Paths in these are not yet resolved. They can
 //! be directly created from an ast::TypeRef, without further queries.
 
-use ra_syntax::ast;
+use ra_syntax::ast::{self, TypeAscriptionOwner};
 
 use crate::Path;
 
@@ -81,7 +81,7 @@ impl TypeRef {
             FnPointerType(inner) => {
                 let ret_ty = TypeRef::from_ast_opt(inner.ret_type().and_then(|rt| rt.type_ref()));
                 let mut params = if let Some(pl) = inner.param_list() {
-                    pl.params().map(|p| p.type_ref()).map(TypeRef::from_ast_opt).collect()
+                    pl.params().map(|p| p.ascribed_type()).map(TypeRef::from_ast_opt).collect()
                 } else {
                     Vec::new()
                 };
diff --git a/crates/ra_ide_api_light/src/structure.rs b/crates/ra_ide_api_light/src/structure.rs
index dea494daa5a6..ec2c9bbc6557 100644
--- a/crates/ra_ide_api_light/src/structure.rs
+++ b/crates/ra_ide_api_light/src/structure.rs
@@ -2,7 +2,7 @@ use crate::TextRange;
 
 use ra_syntax::{
     algo::visit::{visitor, Visitor},
-    ast::{self, AttrsOwner, NameOwner, TypeParamsOwner},
+    ast::{self, AttrsOwner, NameOwner, TypeParamsOwner, TypeAscriptionOwner},
     AstNode, SourceFile, SyntaxKind, SyntaxNode, WalkEvent,
 };
 
@@ -45,6 +45,12 @@ fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
         decl_with_detail(node, None)
     }
 
+    fn decl_with_ascription<N: NameOwner + AttrsOwner + TypeAscriptionOwner>(
+        node: &N,
+    ) -> Option<StructureNode> {
+        decl_with_type_ref(node, node.ascribed_type())
+    }
+
     fn decl_with_type_ref<N: NameOwner + AttrsOwner>(
         node: &N,
         type_ref: Option<&ast::TypeRef>,
@@ -107,14 +113,14 @@ fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
             decl_with_detail(fn_def, Some(detail))
         })
         .visit(decl::<ast::StructDef>)
-        .visit(|nfd: &ast::NamedFieldDef| decl_with_type_ref(nfd, nfd.type_ref()))
         .visit(decl::<ast::EnumDef>)
         .visit(decl::<ast::EnumVariant>)
         .visit(decl::<ast::TraitDef>)
         .visit(decl::<ast::Module>)
         .visit(|td: &ast::TypeAliasDef| decl_with_type_ref(td, td.type_ref()))
-        .visit(|cd: &ast::ConstDef| decl_with_type_ref(cd, cd.type_ref()))
-        .visit(|sd: &ast::StaticDef| decl_with_type_ref(sd, sd.type_ref()))
+        .visit(decl_with_ascription::<ast::NamedFieldDef>)
+        .visit(decl_with_ascription::<ast::ConstDef>)
+        .visit(decl_with_ascription::<ast::StaticDef>)
         .visit(|im: &ast::ImplBlock| {
             let target_type = im.target_type()?;
             let target_trait = im.target_trait();
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 56fb7c20cfaf..81c709bfb33e 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -31,6 +31,12 @@ pub trait AstToken: AstNode {
     }
 }
 
+pub trait TypeAscriptionOwner: AstNode {
+    fn ascribed_type(&self) -> Option<&TypeRef> {
+        child_opt(self)
+    }
+}
+
 pub trait NameOwner: AstNode {
     fn name(&self) -> Option<&Name> {
         child_opt(self)
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index 4e2705d098fd..7572225b86c7 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -628,11 +628,8 @@ impl ast::NameOwner for ConstDef {}
 impl ast::TypeParamsOwner for ConstDef {}
 impl ast::AttrsOwner for ConstDef {}
 impl ast::DocCommentsOwner for ConstDef {}
-impl ConstDef {
-    pub fn type_ref(&self) -> Option<&TypeRef> {
-        super::child_opt(self)
-    }
-}
+impl ast::TypeAscriptionOwner for ConstDef {}
+impl ConstDef {}
 
 // ContinueExpr
 #[derive(Debug, PartialEq, Eq, Hash)]
@@ -1767,15 +1764,12 @@ impl ToOwned for LetStmt {
 }
 
 
+impl ast::TypeAscriptionOwner for LetStmt {}
 impl LetStmt {
     pub fn pat(&self) -> Option<&Pat> {
         super::child_opt(self)
     }
 
-    pub fn type_ref(&self) -> Option<&TypeRef> {
-        super::child_opt(self)
-    }
-
     pub fn initializer(&self) -> Option<&Expr> {
         super::child_opt(self)
     }
@@ -2592,11 +2586,8 @@ impl ast::VisibilityOwner for NamedFieldDef {}
 impl ast::NameOwner for NamedFieldDef {}
 impl ast::AttrsOwner for NamedFieldDef {}
 impl ast::DocCommentsOwner for NamedFieldDef {}
-impl NamedFieldDef {
-    pub fn type_ref(&self) -> Option<&TypeRef> {
-        super::child_opt(self)
-    }
-}
+impl ast::TypeAscriptionOwner for NamedFieldDef {}
+impl NamedFieldDef {}
 
 // NamedFieldDefList
 #[derive(Debug, PartialEq, Eq, Hash)]
@@ -2774,14 +2765,11 @@ impl ToOwned for Param {
 }
 
 
+impl ast::TypeAscriptionOwner for Param {}
 impl Param {
     pub fn pat(&self) -> Option<&Pat> {
         super::child_opt(self)
     }
-
-    pub fn type_ref(&self) -> Option<&TypeRef> {
-        super::child_opt(self)
-    }
 }
 
 // ParamList
@@ -3685,11 +3673,8 @@ impl ToOwned for SelfParam {
 }
 
 
+impl ast::TypeAscriptionOwner for SelfParam {}
 impl SelfParam {
-    pub fn type_ref(&self) -> Option<&TypeRef> {
-        super::child_opt(self)
-    }
-
     pub fn self_kw(&self) -> Option<&SelfKw> {
         super::child_opt(self)
     }
@@ -3820,11 +3805,8 @@ impl ast::NameOwner for StaticDef {}
 impl ast::TypeParamsOwner for StaticDef {}
 impl ast::AttrsOwner for StaticDef {}
 impl ast::DocCommentsOwner for StaticDef {}
-impl StaticDef {
-    pub fn type_ref(&self) -> Option<&TypeRef> {
-        super::child_opt(self)
-    }
-}
+impl ast::TypeAscriptionOwner for StaticDef {}
+impl StaticDef {}
 
 // Stmt
 #[derive(Debug, PartialEq, Eq, Hash)]
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index c7acbbd6c73f..b7a2d1c01b32 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -271,7 +271,15 @@ Grammar(
             ]
         ),
         "NamedFieldDefList": (collections: [["fields", "NamedFieldDef"]]),
-        "NamedFieldDef": ( traits: ["VisibilityOwner", "NameOwner", "AttrsOwner", "DocCommentsOwner"], options: ["TypeRef"] ),
+        "NamedFieldDef": (
+            traits: [
+                "VisibilityOwner",
+                "NameOwner",
+                "AttrsOwner",
+                "DocCommentsOwner",
+                "TypeAscriptionOwner"
+            ]
+        ),
         "PosFieldDefList": (collections: [["fields", "PosFieldDef"]]),
         "PosFieldDef": ( traits: ["VisibilityOwner", "AttrsOwner"], options: ["TypeRef"]),
         "EnumDef": ( traits: [
@@ -298,9 +306,9 @@ Grammar(
                 "NameOwner",
                 "TypeParamsOwner",
                 "AttrsOwner",
-                "DocCommentsOwner"
+                "DocCommentsOwner",
+                "TypeAscriptionOwner",
             ],
-            options: ["TypeRef"]
         ),
         "StaticDef": (
             traits: [
@@ -308,9 +316,9 @@ Grammar(
                 "NameOwner",
                 "TypeParamsOwner",
                 "AttrsOwner",
-                "DocCommentsOwner"
+                "DocCommentsOwner",
+                "TypeAscriptionOwner",
             ],
-            options: ["TypeRef"]
         ),
         "TypeAliasDef": (
             traits: [
@@ -569,11 +577,15 @@ Grammar(
         "ExprStmt": (
             options: [ ["expr", "Expr"] ]
         ),
-        "LetStmt": ( options: [
-            ["pat", "Pat"],
-            ["type_ref", "TypeRef"],
-            ["initializer", "Expr"],
-        ]),
+        "LetStmt": (
+            options: [
+                ["pat", "Pat"],
+                ["initializer", "Expr"],
+            ],
+            traits: [
+                "TypeAscriptionOwner",
+            ]
+        ),
         "Condition": (
             options: [ "Pat", "Expr" ]
         ),
@@ -595,10 +607,18 @@ Grammar(
                 ["params", "Param"]
             ]
         ),
-        "SelfParam": (options: ["TypeRef", "SelfKw"]),
+        "SelfParam": (
+            options: ["SelfKw"],
+            traits: [
+                "TypeAscriptionOwner",
+            ]
+        ),
         "SelfKw": (),
         "Param": (
-            options: [ "Pat", "TypeRef" ],
+            options: [ "Pat" ],
+            traits: [
+                "TypeAscriptionOwner",
+            ]
         ),
         "UseItem": (
             traits: ["AttrsOwner"],