diff --git a/src/test/ui/unboxed-closures/issue-30904.rs b/src/test/ui/unboxed-closures/issue-30904.rs
deleted file mode 100644
index eec5e962b431e..0000000000000
--- a/src/test/ui/unboxed-closures/issue-30904.rs
+++ /dev/null
@@ -1,36 +0,0 @@
-#![feature(fn_traits, unboxed_closures)]
-
-fn test<F: for<'x> FnOnce<(&'x str,)>>(_: F) {}
-
-struct Compose<F,G>(F,G);
-impl<T,F,G> FnOnce<(T,)> for Compose<F,G>
-where F: FnOnce<(T,)>, G: FnOnce<(F::Output,)> {
-    type Output = G::Output;
-    extern "rust-call" fn call_once(self, (x,): (T,)) -> G::Output {
-        (self.1)((self.0)(x))
-    }
-}
-
-struct Str<'a>(&'a str);
-fn mk_str<'a>(s: &'a str) -> Str<'a> { Str(s) }
-
-fn main() {
-    let _: for<'a> fn(&'a str) -> Str<'a> = mk_str;
-    // expected concrete lifetime, found bound lifetime parameter 'a
-    let _: for<'a> fn(&'a str) -> Str<'a> = Str;
-    //~^ ERROR: mismatched types
-
-    test(|_: &str| {});
-    test(mk_str);
-    // expected concrete lifetime, found bound lifetime parameter 'x
-    test(Str); //~ ERROR: type mismatch in function arguments
-
-    test(Compose(|_: &str| {}, |_| {}));
-    test(Compose(mk_str, |_| {}));
-    // internal compiler error: cannot relate bound region:
-    //   ReLateBound(DebruijnIndex { depth: 2 },
-    //     BrNamed(DefId { krate: 0, node: DefIndex(6) => test::'x }, 'x(65)))
-    //<= ReSkolemized(0,
-    //     BrNamed(DefId { krate: 0, node: DefIndex(6) => test::'x }, 'x(65)))
-    test(Compose(Str, |_| {}));
-}
diff --git a/src/test/ui/unboxed-closures/issue-30904.stderr b/src/test/ui/unboxed-closures/issue-30904.stderr
deleted file mode 100644
index 943cbe0ccc297..0000000000000
--- a/src/test/ui/unboxed-closures/issue-30904.stderr
+++ /dev/null
@@ -1,24 +0,0 @@
-error[E0308]: mismatched types
-  --> $DIR/issue-30904.rs:20:45
-   |
-LL |     let _: for<'a> fn(&'a str) -> Str<'a> = Str;
-   |                                             ^^^ expected concrete lifetime, found bound lifetime parameter 'a
-   |
-   = note: expected type `for<'a> fn(&'a str) -> Str<'a>`
-              found type `fn(&str) -> Str<'_> {Str::<'_>}`
-
-error[E0631]: type mismatch in function arguments
-  --> $DIR/issue-30904.rs:26:10
-   |
-LL | fn test<F: for<'x> FnOnce<(&'x str,)>>(_: F) {}
-   |    ----    -------------------------- required by this bound in `test`
-...
-LL | struct Str<'a>(&'a str);
-   | ------------------------ found signature of `fn(&str) -> _`
-...
-LL |     test(Str);
-   |          ^^^ expected signature of `for<'x> fn(&'x str) -> _`
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/unboxed-closures/issue-30906.rs b/src/test/ui/unboxed-closures/issue-30906.rs
new file mode 100644
index 0000000000000..03cce83277515
--- /dev/null
+++ b/src/test/ui/unboxed-closures/issue-30906.rs
@@ -0,0 +1,18 @@
+#![feature(fn_traits, unboxed_closures)]
+
+fn test<F: for<'x> FnOnce<(&'x str,)>>(_: F) {}
+
+struct Compose<F,G>(F,G);
+impl<T,F,G> FnOnce<(T,)> for Compose<F,G>
+where F: FnOnce<(T,)>, G: FnOnce<(F::Output,)> {
+    type Output = G::Output;
+    extern "rust-call" fn call_once(self, (x,): (T,)) -> G::Output {
+        (self.1)((self.0)(x))
+    }
+}
+
+fn bad<T>(f: fn(&'static str) -> T) {
+    test(Compose(f, |_| {})); //~ ERROR: mismatched types
+}
+
+fn main() {}
diff --git a/src/test/ui/unboxed-closures/issue-30906.stderr b/src/test/ui/unboxed-closures/issue-30906.stderr
new file mode 100644
index 0000000000000..5c3a1154e74c1
--- /dev/null
+++ b/src/test/ui/unboxed-closures/issue-30906.stderr
@@ -0,0 +1,12 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-30906.rs:15:5
+   |
+LL |     test(Compose(f, |_| {}));
+   |     ^^^^ one type is more general than the other
+   |
+   = note: expected type `std::ops::FnOnce<(&'x str,)>`
+              found type `std::ops::FnOnce<(&str,)>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.