diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 2850e7a6b44e9..357b57141f649 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -488,6 +488,17 @@ pub struct MissingDoc {
 
     /// Private traits or trait items that leaked through. Don't check their methods.
     private_traits: FxHashSet<hir::HirId>,
+
+    /// In case we have:
+    ///
+    /// ```
+    /// enum Foo { Bar(u32) }
+    /// // or:
+    /// struct Bar(u32);
+    /// ```
+    ///
+    /// No need to require documentation on the unique field.
+    is_ignorable: bool,
 }
 
 impl_lint_pass!(MissingDoc => [MISSING_DOCS]);
@@ -518,7 +529,11 @@ fn has_doc(attr: &ast::Attribute) -> bool {
 
 impl MissingDoc {
     pub fn new() -> MissingDoc {
-        MissingDoc { doc_hidden_stack: vec![false], private_traits: FxHashSet::default() }
+        MissingDoc {
+            doc_hidden_stack: vec![false],
+            private_traits: FxHashSet::default(),
+            is_ignorable: false,
+        }
     }
 
     fn doc_hidden(&self) -> bool {
@@ -616,6 +631,12 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
                 }
                 return;
             }
+            hir::ItemKind::Struct(hir::VariantData::Tuple(fields, _), _) => {
+                if fields.len() < 2 {
+                    // No need to check if there is missing documentation on the field.
+                    self.is_ignorable = true;
+                }
+            }
 
             hir::ItemKind::TyAlias(..)
             | hir::ItemKind::Fn(..)
@@ -661,14 +682,23 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
     }
 
     fn check_field_def(&mut self, cx: &LateContext<'_>, sf: &hir::FieldDef<'_>) {
-        if !sf.is_positional() {
-            let def_id = cx.tcx.hir().local_def_id(sf.hir_id);
-            self.check_missing_docs_attrs(cx, def_id, sf.span, "a", "struct field")
+        if self.is_ignorable {
+            self.is_ignorable = false;
+            return;
         }
+        let def_id = cx.tcx.hir().local_def_id(sf.hir_id);
+        self.check_missing_docs_attrs(cx, def_id, sf.span, "a", "struct field")
     }
 
     fn check_variant(&mut self, cx: &LateContext<'_>, v: &hir::Variant<'_>) {
         self.check_missing_docs_attrs(cx, cx.tcx.hir().local_def_id(v.id), v.span, "a", "variant");
+        if let hir::VariantData::Tuple(fields, _) = v.data {
+            if fields.len() < 2 {
+                // No need to check if there is missing documentation on the variant field.
+                self.is_ignorable = true;
+                return;
+            }
+        }
     }
 }
 
diff --git a/library/core/src/str/pattern.rs b/library/core/src/str/pattern.rs
index 55ac1aa765c1f..7aee5c78e2a74 100644
--- a/library/core/src/str/pattern.rs
+++ b/library/core/src/str/pattern.rs
@@ -161,13 +161,13 @@ pub trait Pattern<'a>: Sized {
 pub enum SearchStep {
     /// Expresses that a match of the pattern has been found at
     /// `haystack[a..b]`.
-    Match(usize, usize),
+    Match(#[allow(missing_docs)] usize, #[allow(missing_docs)] usize),
     /// Expresses that `haystack[a..b]` has been rejected as a possible match
     /// of the pattern.
     ///
     /// Note that there might be more than one `Reject` between two `Match`es,
     /// there is no requirement for them to be combined into one.
-    Reject(usize, usize),
+    Reject(#[allow(missing_docs)] usize, #[allow(missing_docs)] usize),
     /// Expresses that every byte of the haystack has been visited, ending
     /// the iteration.
     Done,
diff --git a/library/std/src/path.rs b/library/std/src/path.rs
index 2a9c361c18afc..7464666abe306 100644
--- a/library/std/src/path.rs
+++ b/library/std/src/path.rs
@@ -147,8 +147,12 @@ pub enum Prefix<'a> {
     /// server's hostname and a share name.
     #[stable(feature = "rust1", since = "1.0.0")]
     VerbatimUNC(
-        #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
-        #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[allow(missing_docs)]
+        &'a OsStr,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[allow(missing_docs)]
+        &'a OsStr,
     ),
 
     /// Verbatim disk prefix, e.g., `\\?\C:`.
@@ -171,8 +175,12 @@ pub enum Prefix<'a> {
     /// UNC prefixes consist of the server's hostname and a share name.
     #[stable(feature = "rust1", since = "1.0.0")]
     UNC(
-        #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
-        #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[allow(missing_docs)]
+        &'a OsStr,
+        #[stable(feature = "rust1", since = "1.0.0")]
+        #[allow(missing_docs)]
+        &'a OsStr,
     ),
 
     /// Prefix `C:` for the given disk drive.
diff --git a/src/test/rustdoc-ui/missing-doc-tuple-variant.rs b/src/test/rustdoc-ui/missing-doc-tuple-variant.rs
new file mode 100644
index 0000000000000..322c5053a5827
--- /dev/null
+++ b/src/test/rustdoc-ui/missing-doc-tuple-variant.rs
@@ -0,0 +1,15 @@
+// compile-flags: -Z unstable-options --check
+
+#![deny(missing_docs)]
+
+//! crate level doc
+
+/// Enum doc.
+pub enum Foo {
+    /// Variant doc.
+    Foo(String),
+    /// Variant Doc.
+    Bar(String, u32),
+    //~^ ERROR
+    //~^^ ERROR
+}
diff --git a/src/test/rustdoc-ui/missing-doc-tuple-variant.stderr b/src/test/rustdoc-ui/missing-doc-tuple-variant.stderr
new file mode 100644
index 0000000000000..49768627dd000
--- /dev/null
+++ b/src/test/rustdoc-ui/missing-doc-tuple-variant.stderr
@@ -0,0 +1,20 @@
+error: missing documentation for a struct field
+  --> $DIR/missing-doc-tuple-variant.rs:12:9
+   |
+LL |     Bar(String, u32),
+   |         ^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/missing-doc-tuple-variant.rs:3:9
+   |
+LL | #![deny(missing_docs)]
+   |         ^^^^^^^^^^^^
+
+error: missing documentation for a struct field
+  --> $DIR/missing-doc-tuple-variant.rs:12:17
+   |
+LL |     Bar(String, u32),
+   |                 ^^^
+
+error: aborting due to 2 previous errors
+