diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index 5f1b655c6b60..d3bf9f0ec4a6 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -417,7 +417,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// minimum values.
     ///
     /// For example:
-    /// ```
+    /// ```ignore (illustrative)
     /// fn foo<'a, 'b>( /* ... */ ) where 'a: 'b { /* ... */ }
     /// ```
     /// would initialize two variables like so:
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index ca57c4f31641..5024c85e2a8a 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -356,7 +356,7 @@ impl DefKind {
 /// For example, everything prefixed with `/* Res */` in this example has
 /// an associated `Res`:
 ///
-/// ```
+/// ```ignore (illustrative)
 /// fn str_to_string(s: & /* Res */ str) -> /* Res */ String {
 ///     /* Res */ String::from(/* Res */ s)
 /// }
diff --git a/compiler/rustc_mir_dataflow/src/impls/initialized.rs b/compiler/rustc_mir_dataflow/src/impls/initialized.rs
index 085757f0fb6e..ebf43300f98a 100644
--- a/compiler/rustc_mir_dataflow/src/impls/initialized.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/initialized.rs
@@ -108,6 +108,7 @@ impl<'tcx> MaybePlacesSwitchIntData<'tcx> {
 ///
 /// ```rust
 /// struct S;
+/// #[rustfmt::skip]
 /// fn foo(pred: bool) {                        // maybe-init:
 ///                                             // {}
 ///     let a = S; let mut b = S; let c; let d; // {a, b}
@@ -197,6 +198,7 @@ impl<'a, 'tcx> HasMoveData<'tcx> for MaybeInitializedPlaces<'a, 'tcx> {
 ///
 /// ```rust
 /// struct S;
+/// #[rustfmt::skip]
 /// fn foo(pred: bool) {                        // maybe-uninit:
 ///                                             // {a, b, c, d}
 ///     let a = S; let mut b = S; let c; let d; // {      c, d}
@@ -289,6 +291,7 @@ impl<'tcx> HasMoveData<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
 ///
 /// ```rust
 /// struct S;
+/// #[rustfmt::skip]
 /// fn foo(pred: bool) {                        // ever-init:
 ///                                             // {          }
 ///     let a = S; let mut b = S; let c; let d; // {a, b      }