diff --git a/src/doc/rustc/src/lints/listing/deny-by-default.md b/src/doc/rustc/src/lints/listing/deny-by-default.md
index 466a748bcee..dc5a9e44acf 100644
--- a/src/doc/rustc/src/lints/listing/deny-by-default.md
+++ b/src/doc/rustc/src/lints/listing/deny-by-default.md
@@ -122,6 +122,46 @@ error: literal out of range for u8
   |
 ```
 
+## patterns-in-fns-without-body
+
+This lint detects patterns in functions without body were that were
+previously erroneously allowed. Some example code that triggers this lint:
+
+```rust,compile_fail
+trait Trait {
+    fn foo(mut arg: u8);
+}
+```
+
+This will produce:
+
+```text
+warning: patterns aren't allowed in methods without bodies
+ --> src/main.rs:2:12
+  |
+2 |     fn foo(mut arg: u8);
+  |            ^^^^^^^
+  |
+  = note: `#[warn(patterns_in_fns_without_body)]` on by default
+  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+  = note: for more information, see issue #35203 <https://github.com/rust-lang/rust/issues/35203>
+```
+
+To fix this, remove the pattern; it can be used in the implementation without
+being used in the definition. That is:
+
+```rust
+trait Trait {
+    fn foo(arg: u8);
+}
+
+impl Trait for i32 {
+    fn foo(mut arg: u8) {
+
+    }
+}
+```
+
 ## pub-use-of-private-extern-crate
 
 This lint detects a specific situation of re-exporting a private `extern crate`;
diff --git a/src/doc/rustc/src/lints/listing/warn-by-default.md b/src/doc/rustc/src/lints/listing/warn-by-default.md
index 813d7c4bafe..77642a850fa 100644
--- a/src/doc/rustc/src/lints/listing/warn-by-default.md
+++ b/src/doc/rustc/src/lints/listing/warn-by-default.md
@@ -307,46 +307,6 @@ warning: path statement with no effect
   |
 ```
 
-## patterns-in-fns-without-body
-
-This lint detects patterns in functions without body were that were
-previously erroneously allowed. Some example code that triggers this lint:
-
-```rust
-trait Trait {
-    fn foo(mut arg: u8);
-}
-```
-
-This will produce:
-
-```text
-warning: patterns aren't allowed in methods without bodies
- --> src/main.rs:2:12
-  |
-2 |     fn foo(mut arg: u8);
-  |            ^^^^^^^
-  |
-  = note: `#[warn(patterns_in_fns_without_body)]` on by default
-  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-  = note: for more information, see issue #35203 <https://github.com/rust-lang/rust/issues/35203>
-```
-
-To fix this, remove the pattern; it can be used in the implementation without
-being used in the definition. That is:
-
-```rust
-trait Trait {
-    fn foo(arg: u8);
-}
-
-impl Trait for i32 {
-    fn foo(mut arg: u8) {
-
-    }
-}
-```
-
 ## plugin-as-library
 
 This lint detects when compiler plugins are used as ordinary library in
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index baa1075e6b3..f8a592d22c1 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -189,7 +189,7 @@ declare_lint! {
 
 declare_lint! {
     pub PATTERNS_IN_FNS_WITHOUT_BODY,
-    Warn,
+    Deny,
     "patterns in functions without body were erroneously allowed",
     @future_incompatible = FutureIncompatibleInfo {
         reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",