diff --git a/Cargo.lock b/Cargo.lock
index b28c6d98b8..3a34978b13 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -936,7 +936,6 @@ dependencies = [
  "ra_db",
  "ra_fmt",
  "ra_hir",
- "ra_hir_def",
  "ra_ide_db",
  "ra_prof",
  "ra_syntax",
diff --git a/crates/ra_assists/Cargo.toml b/crates/ra_assists/Cargo.toml
index 488ab7bc87..3bcf58ba4b 100644
--- a/crates/ra_assists/Cargo.toml
+++ b/crates/ra_assists/Cargo.toml
@@ -21,5 +21,4 @@ ra_prof = { path = "../ra_prof" }
 ra_db = { path = "../ra_db" }
 ra_ide_db = { path = "../ra_ide_db" }
 hir = { path = "../ra_hir", package = "ra_hir" }
-hir_def = { path = "../ra_hir_def", package = "ra_hir_def" }
 test_utils = { path = "../test_utils" }
diff --git a/crates/ra_assists/src/ast_transform.rs b/crates/ra_assists/src/ast_transform.rs
index d81218bc80..4001ca73c3 100644
--- a/crates/ra_assists/src/ast_transform.rs
+++ b/crates/ra_assists/src/ast_transform.rs
@@ -1,8 +1,7 @@
 //! `AstTransformer`s are functions that replace nodes in an AST and can be easily combined.
 use rustc_hash::FxHashMap;
 
-use hir::{PathResolution, SemanticsScope};
-use hir_def::type_ref::TypeRef;
+use hir::{HirDisplay, PathResolution, SemanticsScope};
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
     algo::SyntaxRewriter,
@@ -61,14 +60,18 @@ impl<'a> SubstituteTypeParams<'a> {
             .zip(substs.into_iter().map(Some).chain(std::iter::repeat(None)))
             .filter_map(|(k, v)| match v {
                 Some(v) => Some((k, v)),
-                None => match k.default(source_scope.db)? {
-                    TypeRef::Path(path) => Some((
+                None => {
+                    let default = k.default(source_scope.db)?;
+                    Some((
                         k,
-                        ast::make::type_arg(&format!("{}", path.mod_path().as_ident()?))
-                            .type_ref()?,
-                    )),
-                    _ => None,
-                },
+                        ast::make::type_arg(
+                            &default
+                                .display_source_code(source_scope.db, source_scope.module()?.into())
+                                .ok()?,
+                        )
+                        .type_ref()?,
+                    ))
+                }
             })
             .collect();
         return SubstituteTypeParams {
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 3c56f39c13..3936f5aaa0 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -990,9 +990,10 @@ impl TypeParam {
         }
     }
 
-    pub fn default(self, db: &dyn HirDatabase) -> Option<TypeRef> {
-        let params = db.generic_params(self.id.parent);
-        params.types[self.id.local_id].default.clone()
+    pub fn default(self, db: &dyn HirDatabase) -> Option<Ty> {
+        let params = db.generic_defaults(self.id.parent);
+        let local_idx: u32 = self.id.local_id.into_raw().into();
+        params.get(local_idx as usize).map(|d| d.clone())
     }
 }