diff --git a/clippy_lints/src/extra_unused_type_parameters.rs b/clippy_lints/src/extra_unused_type_parameters.rs
index c0b0fd88d9e1..2b54bfdd3258 100644
--- a/clippy_lints/src/extra_unused_type_parameters.rs
+++ b/clippy_lints/src/extra_unused_type_parameters.rs
@@ -102,7 +102,7 @@ impl<'cx, 'tcx> TypeWalker<'cx, 'tcx> {
     fn emit_sugg(&self, spans: Vec<Span>, msg: String, help: &'static str) {
         let suggestions: Vec<(Span, String)> = spans.iter().copied().zip(std::iter::repeat(String::new())).collect();
         span_lint_and_then(self.cx, EXTRA_UNUSED_TYPE_PARAMETERS, spans, msg, |diag| {
-            diag.multipart_suggestion(help, suggestions, Applicability::MachineApplicable);
+            diag.multipart_suggestion(help, suggestions, Applicability::MaybeIncorrect);
         });
     }
 
diff --git a/tests/ui/extra_unused_type_parameters_unfixable.rs b/tests/ui/extra_unused_type_parameters_unfixable.rs
index 87ce517a0a45..ef9e98e247ed 100644
--- a/tests/ui/extra_unused_type_parameters_unfixable.rs
+++ b/tests/ui/extra_unused_type_parameters_unfixable.rs
@@ -1,3 +1,5 @@
+//@no-rustfix
+
 #![warn(clippy::extra_unused_type_parameters)]
 
 fn unused_where_clause<T, U>(x: U)
@@ -24,4 +26,15 @@ where
     unimplemented!();
 }
 
+mod issue15884 {
+    fn unused_ty<T>(x: u8) {
+        //~^ extra_unused_type_parameters
+        unimplemented!()
+    }
+
+    fn main() {
+        unused_ty::<String>(0);
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/extra_unused_type_parameters_unfixable.stderr b/tests/ui/extra_unused_type_parameters_unfixable.stderr
index 0765c4160936..bf70a1cb5421 100644
--- a/tests/ui/extra_unused_type_parameters_unfixable.stderr
+++ b/tests/ui/extra_unused_type_parameters_unfixable.stderr
@@ -1,5 +1,5 @@
 error: type parameter `T` goes unused in function definition
-  --> tests/ui/extra_unused_type_parameters_unfixable.rs:3:24
+  --> tests/ui/extra_unused_type_parameters_unfixable.rs:5:24
    |
 LL | fn unused_where_clause<T, U>(x: U)
    |                        ^
@@ -9,7 +9,7 @@ LL | fn unused_where_clause<T, U>(x: U)
    = help: to override `-D warnings` add `#[allow(clippy::extra_unused_type_parameters)]`
 
 error: type parameters go unused in function definition: T, V
-  --> tests/ui/extra_unused_type_parameters_unfixable.rs:11:30
+  --> tests/ui/extra_unused_type_parameters_unfixable.rs:13:30
    |
 LL | fn unused_multi_where_clause<T, U, V: Default>(x: U)
    |                              ^     ^^^^^^^^^^
@@ -17,12 +17,18 @@ LL | fn unused_multi_where_clause<T, U, V: Default>(x: U)
    = help: consider removing the parameters
 
 error: type parameters go unused in function definition: T, U, V
-  --> tests/ui/extra_unused_type_parameters_unfixable.rs:19:28
+  --> tests/ui/extra_unused_type_parameters_unfixable.rs:21:28
    |
 LL | fn unused_all_where_clause<T, U: Default, V: Default>()
    |                            ^  ^^^^^^^^^^  ^^^^^^^^^^
    |
    = help: consider removing the parameters
 
-error: aborting due to 3 previous errors
+error: type parameter `T` goes unused in function definition
+  --> tests/ui/extra_unused_type_parameters_unfixable.rs:30:17
+   |
+LL |     fn unused_ty<T>(x: u8) {
+   |                 ^^^ help: consider removing the parameter
+
+error: aborting due to 4 previous errors