diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 208e8f723f407..017ce0a494eb3 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -247,6 +247,9 @@ code, pre, a.test-arrow {
pre {
padding: 14px;
}
+.type-decl pre {
+ overflow-x: auto;
+}
.source .content pre {
padding: 20px;
diff --git a/src/test/rustdoc-gui/src/lib2/lib.rs b/src/test/rustdoc-gui/src/lib2/lib.rs
index ec8ab339e2804..0466909479b67 100644
--- a/src/test/rustdoc-gui/src/lib2/lib.rs
+++ b/src/test/rustdoc-gui/src/lib2/lib.rs
@@ -47,3 +47,10 @@ pub mod sub_mod {
/// ```
pub struct Foo;
}
+
+pub mod long_trait {
+ use std::ops::DerefMut;
+
+ pub trait ALongNameBecauseItHelpsTestingTheCurrentProblem: DerefMut<Target = u32>
+ + From<u128> + Send + Sync + AsRef<str> + 'static {}
+}
diff --git a/src/test/rustdoc-gui/type-declation-overflow.goml b/src/test/rustdoc-gui/type-declation-overflow.goml
new file mode 100644
index 0000000000000..0a316e220a42c
--- /dev/null
+++ b/src/test/rustdoc-gui/type-declation-overflow.goml
@@ -0,0 +1,8 @@
+// This test ensures that the type declaration content overflow is handled inside the <pre> directly.
+goto: file://|DOC_PATH|/lib2/long_trait/trait.ALongNameBecauseItHelpsTestingTheCurrentProblem.html
+// We set a fixed size so there is no chance of "random" resize.
+size: (1100, 800)
+// Logically, the <body> scroll width should be the width of the window.
+assert-property: ("body", {"scrollWidth": "1100"})
+// However, since there is overflow in the type declaration, its scroll width is bigger.
+assert-property: (".type-decl pre", {"scrollWidth": "1324"})