diff --git a/rustfmt-core/rustfmt-lib/src/spanned.rs b/rustfmt-core/rustfmt-lib/src/spanned.rs
index b2a70dd5cec..19ed7137c85 100644
--- a/rustfmt-core/rustfmt-lib/src/spanned.rs
+++ b/rustfmt-core/rustfmt-lib/src/spanned.rs
@@ -104,7 +104,7 @@ impl Spanned for ast::Arm {
 impl Spanned for ast::Param {
     fn span(&self) -> Span {
         if crate::items::is_named_param(self) {
-            mk_sp(self.pat.span.lo(), self.ty.span.hi())
+            mk_sp(crate::items::span_lo_for_param(self), self.ty.span.hi())
         } else {
             self.ty.span
         }
diff --git a/rustfmt-core/rustfmt-lib/tests/source/issue_4032.rs b/rustfmt-core/rustfmt-lib/tests/source/issue_4032.rs
new file mode 100644
index 00000000000..11ded074c34
--- /dev/null
+++ b/rustfmt-core/rustfmt-lib/tests/source/issue_4032.rs
@@ -0,0 +1,4 @@
+fn a1(#[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] a: u8) {}
+fn b1(#[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] bb: u8) {}
+fn a2(#[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] a: u8) {}
+fn b2(#[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] bb: u8) {}
diff --git a/rustfmt-core/rustfmt-lib/tests/target/issue_4032.rs b/rustfmt-core/rustfmt-lib/tests/target/issue_4032.rs
new file mode 100644
index 00000000000..9c926ceaaba
--- /dev/null
+++ b/rustfmt-core/rustfmt-lib/tests/target/issue_4032.rs
@@ -0,0 +1,16 @@
+fn a1(
+    #[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] a: u8,
+) {
+}
+fn b1(
+    #[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] bb: u8,
+) {
+}
+fn a2(
+    #[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] a: u8,
+) {
+}
+fn b2(
+    #[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa] bb: u8,
+) {
+}