diff --git a/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr b/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr
index 17969137a988..097e4c75065c 100644
--- a/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr
+++ b/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr
@@ -72,4 +72,5 @@ LL |         let _h = to_fn_mut(move || { set(&mut z); to_fn(move || z = 42); })
 
 error: aborting due to 6 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/borrowck-assign-to-andmut-in-aliasable-loc.stderr b/src/test/ui/borrowck/borrowck-assign-to-andmut-in-aliasable-loc.stderr
index 38fcfbfc2a02..d8ccf36852a5 100644
--- a/src/test/ui/borrowck/borrowck-assign-to-andmut-in-aliasable-loc.stderr
+++ b/src/test/ui/borrowck/borrowck-assign-to-andmut-in-aliasable-loc.stderr
@@ -16,3 +16,4 @@ LL |     *s.pointer += 1;
 
 error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/borrowck-assign-to-constants.stderr b/src/test/ui/borrowck/borrowck-assign-to-constants.stderr
index 800003caa0f3..864d933da127 100644
--- a/src/test/ui/borrowck/borrowck-assign-to-constants.stderr
+++ b/src/test/ui/borrowck/borrowck-assign-to-constants.stderr
@@ -6,3 +6,4 @@ LL |     foo = 6;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/borrowck-borrow-mut-base-ptr-in-aliasable-loc.stderr b/src/test/ui/borrowck/borrowck-borrow-mut-base-ptr-in-aliasable-loc.stderr
index 8115e3150fbc..1fdeb812bf8b 100644
--- a/src/test/ui/borrowck/borrowck-borrow-mut-base-ptr-in-aliasable-loc.stderr
+++ b/src/test/ui/borrowck/borrowck-borrow-mut-base-ptr-in-aliasable-loc.stderr
@@ -27,5 +27,5 @@ LL |     let x:  &mut isize = &mut **t0;
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0502, E0596.
+Some errors have detailed explanations: E0502, E0594, E0596.
 For more information about an error, try `rustc --explain E0502`.
diff --git a/src/test/ui/borrowck/borrowck-borrow-overloaded-auto-deref.stderr b/src/test/ui/borrowck/borrowck-borrow-overloaded-auto-deref.stderr
index d262c578843a..6f2b20285b93 100644
--- a/src/test/ui/borrowck/borrowck-borrow-overloaded-auto-deref.stderr
+++ b/src/test/ui/borrowck/borrowck-borrow-overloaded-auto-deref.stderr
@@ -112,4 +112,5 @@ LL |     *x.y_mut() = 3;
 
 error: aborting due to 14 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/borrowck-borrow-overloaded-deref.stderr b/src/test/ui/borrowck/borrowck-borrow-overloaded-deref.stderr
index 8cacc29414d7..246a7981ae3c 100644
--- a/src/test/ui/borrowck/borrowck-borrow-overloaded-deref.stderr
+++ b/src/test/ui/borrowck/borrowck-borrow-overloaded-deref.stderr
@@ -56,4 +56,5 @@ LL |     **x = 3;
 
 error: aborting due to 7 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/borrowck-closures-unique.stderr b/src/test/ui/borrowck/borrowck-closures-unique.stderr
index 2ed08b83c58b..64c2f419ffa6 100644
--- a/src/test/ui/borrowck/borrowck-closures-unique.stderr
+++ b/src/test/ui/borrowck/borrowck-closures-unique.stderr
@@ -50,5 +50,5 @@ LL |     let c1 = |y: &'static mut isize| x = y;
 
 error: aborting due to 4 previous errors
 
-Some errors have detailed explanations: E0500, E0524.
+Some errors have detailed explanations: E0500, E0524, E0594.
 For more information about an error, try `rustc --explain E0500`.
diff --git a/src/test/ui/borrowck/borrowck-issue-14498.stderr b/src/test/ui/borrowck/borrowck-issue-14498.stderr
index fec4c27520cf..ae9167757a0a 100644
--- a/src/test/ui/borrowck/borrowck-issue-14498.stderr
+++ b/src/test/ui/borrowck/borrowck-issue-14498.stderr
@@ -96,4 +96,5 @@ LL |     drop(p);
 
 error: aborting due to 9 previous errors
 
-For more information about this error, try `rustc --explain E0506`.
+Some errors have detailed explanations: E0506, E0594.
+For more information about an error, try `rustc --explain E0506`.
diff --git a/src/test/ui/borrowck/borrowck-overloaded-index-ref-index.stderr b/src/test/ui/borrowck/borrowck-overloaded-index-ref-index.stderr
index 84fe17d85448..2f92c1ebe5e1 100644
--- a/src/test/ui/borrowck/borrowck-overloaded-index-ref-index.stderr
+++ b/src/test/ui/borrowck/borrowck-overloaded-index-ref-index.stderr
@@ -31,4 +31,5 @@ LL |     s[2] = 20;
 
 error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0502`.
+Some errors have detailed explanations: E0502, E0594.
+For more information about an error, try `rustc --explain E0502`.
diff --git a/src/test/ui/borrowck/index-mut-help.stderr b/src/test/ui/borrowck/index-mut-help.stderr
index 47f2171f88c8..baf649f9127a 100644
--- a/src/test/ui/borrowck/index-mut-help.stderr
+++ b/src/test/ui/borrowck/index-mut-help.stderr
@@ -24,4 +24,5 @@ LL |     let _ = &mut map["peter"];
 
 error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/issue-45983.nll.stderr b/src/test/ui/borrowck/issue-45983.nll.stderr
index dff0b4cebace..49d6c2473f6a 100644
--- a/src/test/ui/borrowck/issue-45983.nll.stderr
+++ b/src/test/ui/borrowck/issue-45983.nll.stderr
@@ -18,3 +18,4 @@ LL |     give_any(|y| x = Some(y));
 
 error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/issue-54499-field-mutation-of-moved-out.stderr b/src/test/ui/borrowck/issue-54499-field-mutation-of-moved-out.stderr
index 7dfd71c81c30..b7623a54056d 100644
--- a/src/test/ui/borrowck/issue-54499-field-mutation-of-moved-out.stderr
+++ b/src/test/ui/borrowck/issue-54499-field-mutation-of-moved-out.stderr
@@ -84,4 +84,5 @@ LL |         v.y = 2;
 
 error: aborting due to 9 previous errors
 
-For more information about this error, try `rustc --explain E0382`.
+Some errors have detailed explanations: E0382, E0594.
+For more information about an error, try `rustc --explain E0382`.
diff --git a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr
index f1d28eed922a..1cdcc18632c6 100644
--- a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr
+++ b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr
@@ -50,4 +50,5 @@ LL |         || { &mut x.0; };
 
 error: aborting due to 6 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr
index f1d28eed922a..1cdcc18632c6 100644
--- a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr
+++ b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr
@@ -50,4 +50,5 @@ LL |         || { &mut x.0; };
 
 error: aborting due to 6 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/mutability-errors.stderr b/src/test/ui/borrowck/mutability-errors.stderr
index 545de5d0e75b..72547a40352c 100644
--- a/src/test/ui/borrowck/mutability-errors.stderr
+++ b/src/test/ui/borrowck/mutability-errors.stderr
@@ -375,4 +375,5 @@ LL |     &mut X.0;
 
 error: aborting due to 38 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/borrowck/reassignment_immutable_fields_overlapping.stderr b/src/test/ui/borrowck/reassignment_immutable_fields_overlapping.stderr
index 5f346708eb61..0eae2c71e4a1 100644
--- a/src/test/ui/borrowck/reassignment_immutable_fields_overlapping.stderr
+++ b/src/test/ui/borrowck/reassignment_immutable_fields_overlapping.stderr
@@ -15,4 +15,5 @@ LL |     x.b = 22;
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0381`.
+Some errors have detailed explanations: E0381, E0594.
+For more information about an error, try `rustc --explain E0381`.
diff --git a/src/test/ui/borrowck/reassignment_immutable_fields_twice.stderr b/src/test/ui/borrowck/reassignment_immutable_fields_twice.stderr
index 14f0fee84c9a..f55e1a27f475 100644
--- a/src/test/ui/borrowck/reassignment_immutable_fields_twice.stderr
+++ b/src/test/ui/borrowck/reassignment_immutable_fields_twice.stderr
@@ -15,4 +15,5 @@ LL |     x.0 = 1;
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0381`.
+Some errors have detailed explanations: E0381, E0594.
+For more information about an error, try `rustc --explain E0381`.
diff --git a/src/test/ui/cannot-mutate-captured-non-mut-var.stderr b/src/test/ui/cannot-mutate-captured-non-mut-var.stderr
index 2961497ef9f5..2d6e83c9e82f 100644
--- a/src/test/ui/cannot-mutate-captured-non-mut-var.stderr
+++ b/src/test/ui/cannot-mutate-captured-non-mut-var.stderr
@@ -16,4 +16,5 @@ LL |     to_fn_once(move|| { s.read_to_end(&mut Vec::new()); });
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/closures/closure-immutable-outer-variable.stderr b/src/test/ui/closures/closure-immutable-outer-variable.stderr
index 558c9caeff33..7e60f3cd8ffa 100644
--- a/src/test/ui/closures/closure-immutable-outer-variable.stderr
+++ b/src/test/ui/closures/closure-immutable-outer-variable.stderr
@@ -8,3 +8,4 @@ LL |     foo(Box::new(move || y = false) as Box<_>);
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/consts/miri_unleashed/mutable_references.stderr b/src/test/ui/consts/miri_unleashed/mutable_references.stderr
index e8a867307ce1..b9c0af33c39c 100644
--- a/src/test/ui/consts/miri_unleashed/mutable_references.stderr
+++ b/src/test/ui/consts/miri_unleashed/mutable_references.stderr
@@ -36,3 +36,4 @@ LL |     *OH_YES = 99;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/did_you_mean/issue-35937.stderr b/src/test/ui/did_you_mean/issue-35937.stderr
index 4f9b6a6134dc..1f578d18a1ce 100644
--- a/src/test/ui/did_you_mean/issue-35937.stderr
+++ b/src/test/ui/did_you_mean/issue-35937.stderr
@@ -24,4 +24,5 @@ LL |     s.x += 1;
 
 error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/did_you_mean/issue-39544.stderr b/src/test/ui/did_you_mean/issue-39544.stderr
index dfaaf6b17dc3..ce0d697238c6 100644
--- a/src/test/ui/did_you_mean/issue-39544.stderr
+++ b/src/test/ui/did_you_mean/issue-39544.stderr
@@ -98,4 +98,5 @@ LL |     *x.0 = 1;
 
 error: aborting due to 12 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/error-codes/E0389.stderr b/src/test/ui/error-codes/E0389.stderr
index 5310367d51a5..c47750b6f4e6 100644
--- a/src/test/ui/error-codes/E0389.stderr
+++ b/src/test/ui/error-codes/E0389.stderr
@@ -8,3 +8,4 @@ LL |     fancy_ref.num = 6;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/error-codes/E0594.stderr b/src/test/ui/error-codes/E0594.stderr
index c00ec4250a70..f4d96f4e45a5 100644
--- a/src/test/ui/error-codes/E0594.stderr
+++ b/src/test/ui/error-codes/E0594.stderr
@@ -6,3 +6,4 @@ LL |     NUM = 20;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/fn/fn-closure-mutable-capture.stderr b/src/test/ui/fn/fn-closure-mutable-capture.stderr
index 8dfae0cbdf29..f7ab56da8de9 100644
--- a/src/test/ui/fn/fn-closure-mutable-capture.stderr
+++ b/src/test/ui/fn/fn-closure-mutable-capture.stderr
@@ -12,3 +12,4 @@ LL |     bar(move || x = 1);
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/immut-function-arguments.stderr b/src/test/ui/immut-function-arguments.stderr
index 7871ba52db9c..7238dd14433c 100644
--- a/src/test/ui/immut-function-arguments.stderr
+++ b/src/test/ui/immut-function-arguments.stderr
@@ -16,3 +16,4 @@ LL |     let _frob = |q: Box<isize>| { *q = 2; };
 
 error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/issues/issue-46023.stderr b/src/test/ui/issues/issue-46023.stderr
index fac696c6fdcb..ca19c2501205 100644
--- a/src/test/ui/issues/issue-46023.stderr
+++ b/src/test/ui/issues/issue-46023.stderr
@@ -9,3 +9,4 @@ LL |         x = 1;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/issues/issue-46604.stderr b/src/test/ui/issues/issue-46604.stderr
index 961b249daeb0..c72f580f2439 100644
--- a/src/test/ui/issues/issue-46604.stderr
+++ b/src/test/ui/issues/issue-46604.stderr
@@ -12,4 +12,5 @@ LL |     buf[0]=2;
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0017`.
+Some errors have detailed explanations: E0017, E0594.
+For more information about an error, try `rustc --explain E0017`.
diff --git a/src/test/ui/issues/issue-51244.stderr b/src/test/ui/issues/issue-51244.stderr
index 8a7e71e0326a..c91083955b82 100644
--- a/src/test/ui/issues/issue-51244.stderr
+++ b/src/test/ui/issues/issue-51244.stderr
@@ -8,3 +8,4 @@ LL |     *my_ref = 0;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/issues/issue-51515.stderr b/src/test/ui/issues/issue-51515.stderr
index 827bb8fe2b89..3c208935f31f 100644
--- a/src/test/ui/issues/issue-51515.stderr
+++ b/src/test/ui/issues/issue-51515.stderr
@@ -18,3 +18,4 @@ LL |     *bar = 64;
 
 error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/mut/mutable-class-fields-2.stderr b/src/test/ui/mut/mutable-class-fields-2.stderr
index a27a82ffe464..15323ce9a975 100644
--- a/src/test/ui/mut/mutable-class-fields-2.stderr
+++ b/src/test/ui/mut/mutable-class-fields-2.stderr
@@ -8,3 +8,4 @@ LL |     self.how_hungry -= 5;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/mut/mutable-class-fields.stderr b/src/test/ui/mut/mutable-class-fields.stderr
index 5391ccc80c5f..40a0dc9b29c2 100644
--- a/src/test/ui/mut/mutable-class-fields.stderr
+++ b/src/test/ui/mut/mutable-class-fields.stderr
@@ -8,3 +8,4 @@ LL |   nyan.how_hungry = 0;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/nll/closure-captures.stderr b/src/test/ui/nll/closure-captures.stderr
index 77f7d815eeb4..b8f5cc86500c 100644
--- a/src/test/ui/nll/closure-captures.stderr
+++ b/src/test/ui/nll/closure-captures.stderr
@@ -156,4 +156,5 @@ LL | |         *x = 1;});
 
 error: aborting due to 12 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/nll/constant-thread-locals-issue-47053.stderr b/src/test/ui/nll/constant-thread-locals-issue-47053.stderr
index 8afb42d66a61..a44acfb5fc35 100644
--- a/src/test/ui/nll/constant-thread-locals-issue-47053.stderr
+++ b/src/test/ui/nll/constant-thread-locals-issue-47053.stderr
@@ -6,3 +6,4 @@ LL |     FOO = 6;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/nll/generator-upvar-mutability.stderr b/src/test/ui/nll/generator-upvar-mutability.stderr
index 1b4e5b89984e..31b061b61d19 100644
--- a/src/test/ui/nll/generator-upvar-mutability.stderr
+++ b/src/test/ui/nll/generator-upvar-mutability.stderr
@@ -9,3 +9,4 @@ LL |         x = 1;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/nll/issue-47388.stderr b/src/test/ui/nll/issue-47388.stderr
index d4064b3f50a3..8d48b00f8d1f 100644
--- a/src/test/ui/nll/issue-47388.stderr
+++ b/src/test/ui/nll/issue-47388.stderr
@@ -8,3 +8,4 @@ LL |     fancy_ref.num = 6;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/nll/issue-51244.stderr b/src/test/ui/nll/issue-51244.stderr
index 8a7e71e0326a..c91083955b82 100644
--- a/src/test/ui/nll/issue-51244.stderr
+++ b/src/test/ui/nll/issue-51244.stderr
@@ -8,3 +8,4 @@ LL |     *my_ref = 0;
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/nll/issue-57989.stderr b/src/test/ui/nll/issue-57989.stderr
index 00a9bab48685..4c416105035d 100644
--- a/src/test/ui/nll/issue-57989.stderr
+++ b/src/test/ui/nll/issue-57989.stderr
@@ -20,4 +20,5 @@ LL |     g;
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0506`.
+Some errors have detailed explanations: E0506, E0594.
+For more information about an error, try `rustc --explain E0506`.
diff --git a/src/test/ui/rfc-2005-default-binding-mode/enum.stderr b/src/test/ui/rfc-2005-default-binding-mode/enum.stderr
index 9d53e6d7887d..d6a89006bc0f 100644
--- a/src/test/ui/rfc-2005-default-binding-mode/enum.stderr
+++ b/src/test/ui/rfc-2005-default-binding-mode/enum.stderr
@@ -18,3 +18,4 @@ LL |         *x += 1;
 
 error: aborting due to 3 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/rfc-2005-default-binding-mode/explicit-mut.stderr b/src/test/ui/rfc-2005-default-binding-mode/explicit-mut.stderr
index 5eace3d263d4..a6f2f3ec3096 100644
--- a/src/test/ui/rfc-2005-default-binding-mode/explicit-mut.stderr
+++ b/src/test/ui/rfc-2005-default-binding-mode/explicit-mut.stderr
@@ -18,3 +18,4 @@ LL |             *n += 1;
 
 error: aborting due to 3 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/suggestions/suggest-ref-mut.stderr b/src/test/ui/suggestions/suggest-ref-mut.stderr
index 241436787571..b4981279a238 100644
--- a/src/test/ui/suggestions/suggest-ref-mut.stderr
+++ b/src/test/ui/suggestions/suggest-ref-mut.stderr
@@ -35,3 +35,4 @@ LL |         ref quo => { *quo = 32; },
 
 error: aborting due to 4 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/thread-local-mutation.stderr b/src/test/ui/thread-local-mutation.stderr
index 7f7738b5d650..e5dc0e72edfc 100644
--- a/src/test/ui/thread-local-mutation.stderr
+++ b/src/test/ui/thread-local-mutation.stderr
@@ -6,3 +6,4 @@ LL |     S = "after";
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.stderr b/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.stderr
index 9fd8aa562f4e..ad5451ced55d 100644
--- a/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.stderr
@@ -71,4 +71,5 @@ LL |     || set(&mut x);
 
 error: aborting due to 8 previous errors
 
-For more information about this error, try `rustc --explain E0596`.
+Some errors have detailed explanations: E0594, E0596.
+For more information about an error, try `rustc --explain E0594`.
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr
index fef6c23a5013..6bba38510b67 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr
@@ -42,3 +42,4 @@ LL | |     });
 
 error: aborting due to 4 previous errors
 
+For more information about this error, try `rustc --explain E0594`.
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-mutated-upvar-from-fn-closure.stderr b/src/test/ui/unboxed-closures/unboxed-closures-mutated-upvar-from-fn-closure.stderr
index 2bc1f01af981..a38c612e1dea 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-mutated-upvar-from-fn-closure.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-mutated-upvar-from-fn-closure.stderr
@@ -16,3 +16,4 @@ LL | |     });
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0594`.