diff --git a/crates/ide_assists/src/handlers/extract_function.rs b/crates/ide_assists/src/handlers/extract_function.rs
index 43e83d683d8..ac7f0959b08 100644
--- a/crates/ide_assists/src/handlers/extract_function.rs
+++ b/crates/ide_assists/src/handlers/extract_function.rs
@@ -831,7 +831,6 @@ fn path_element_of_reference(
     })?;
     stdx::always!(
         matches!(path, ast::Expr::PathExpr(_) | ast::Expr::MacroCall(_)),
-
         "unexpected expression type for variable usage: {:?}",
         path
     );
@@ -2991,11 +2990,7 @@ mod bar {
         check_assist(
             extract_function,
             r#"
-enum Option<T> {
-    #[lang = "None"] None,
-    #[lang = "Some"] Some(T),
-}
-use Option::*;
+//- minicore: option
 fn foo() {
     loop {
         let n = 1;
@@ -3007,11 +3002,6 @@ fn foo() {
 }
 "#,
             r#"
-enum Option<T> {
-    #[lang = "None"] None,
-    #[lang = "Some"] Some(T),
-}
-use Option::*;
 fn foo() {
     loop {
         let n = 1;
diff --git a/crates/ide_completion/src/completions/dot.rs b/crates/ide_completion/src/completions/dot.rs
index 7f75d42988c..286d7cb67ca 100644
--- a/crates/ide_completion/src/completions/dot.rs
+++ b/crates/ide_completion/src/completions/dot.rs
@@ -498,10 +498,7 @@ mod foo {
     fn issue_8931() {
         check(
             r#"
-#[lang = "fn_once"]
-trait FnOnce<Args> {
-    type Output;
-}
+//- minicore: fn
 struct S;
 
 struct Foo;
diff --git a/crates/ide_completion/src/context.rs b/crates/ide_completion/src/context.rs
index 98fb3604285..e49e434fa39 100644
--- a/crates/ide_completion/src/context.rs
+++ b/crates/ide_completion/src/context.rs
@@ -942,13 +942,12 @@ fn foo() -> u32 {
         // FIXME: make this work with `|| $0`
         check_expected_type_and_name(
             r#"
+//- minicore: fn
 fn foo() {
     bar(|| a$0);
 }
 
 fn bar(f: impl FnOnce() -> u32) {}
-#[lang = "fn_once"]
-trait FnOnce { type Output; }
 "#,
             expect![[r#"ty: u32, name: ?"#]],
         );