diff --git a/tests/ui-fulldeps/rustc-dev-remap.only-remap.stderr b/tests/ui-fulldeps/rustc-dev-remap.only-remap.stderr
index d2303ef4bbb5..4a6ca56bf329 100644
--- a/tests/ui-fulldeps/rustc-dev-remap.only-remap.stderr
+++ b/tests/ui-fulldeps/rustc-dev-remap.only-remap.stderr
@@ -4,7 +4,7 @@ error[E0277]: the trait bound `NotAValidResultType: VisitorResult` is not satisf
 LL |     type Result = NotAValidResultType;
    |                   ^^^^^^^^^^^^^^^^^^^ unsatisfied trait bound
    |
-help: the trait `VisitorResult` is not implemented for `NotAValidResultType`
+help: the nightly-only, unstable trait `VisitorResult` is not implemented for `NotAValidResultType`
   --> $DIR/rustc-dev-remap.rs:LL:COL
    |
 LL | struct NotAValidResultType;
diff --git a/tests/ui-fulldeps/rustc-dev-remap.remap-unremap.stderr b/tests/ui-fulldeps/rustc-dev-remap.remap-unremap.stderr
index 50bb60e78d68..18dffdb2cf79 100644
--- a/tests/ui-fulldeps/rustc-dev-remap.remap-unremap.stderr
+++ b/tests/ui-fulldeps/rustc-dev-remap.remap-unremap.stderr
@@ -4,7 +4,7 @@ error[E0277]: the trait bound `NotAValidResultType: VisitorResult` is not satisf
 LL |     type Result = NotAValidResultType;
    |                   ^^^^^^^^^^^^^^^^^^^ unsatisfied trait bound
    |
-help: the trait `VisitorResult` is not implemented for `NotAValidResultType`
+help: the nightly-only, unstable trait `VisitorResult` is not implemented for `NotAValidResultType`
   --> $DIR/rustc-dev-remap.rs:LL:COL
    |
 LL | struct NotAValidResultType;
diff --git a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive-doc-comment-field.stderr b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive-doc-comment-field.stderr
index 72e150dd5178..316f23888bc1 100644
--- a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive-doc-comment-field.stderr
+++ b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive-doc-comment-field.stderr
@@ -7,7 +7,7 @@ LL | #[derive(Diagnostic)]
 LL |     arg: NotIntoDiagArg,
    |          ^^^^^^^^^^^^^^ unsatisfied trait bound
    |
-help: the trait `IntoDiagArg` is not implemented for `NotIntoDiagArg`
+help: the nightly-only, unstable trait `IntoDiagArg` is not implemented for `NotIntoDiagArg`
   --> $DIR/diagnostic-derive-doc-comment-field.rs:28:1
    |
 LL | struct NotIntoDiagArg;
@@ -29,7 +29,7 @@ LL | #[derive(Subdiagnostic)]
 LL |     arg: NotIntoDiagArg,
    |          ^^^^^^^^^^^^^^ unsatisfied trait bound
    |
-help: the trait `IntoDiagArg` is not implemented for `NotIntoDiagArg`
+help: the nightly-only, unstable trait `IntoDiagArg` is not implemented for `NotIntoDiagArg`
   --> $DIR/diagnostic-derive-doc-comment-field.rs:28:1
    |
 LL | struct NotIntoDiagArg;
diff --git a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
index f2244a968769..90ad21ef08f9 100644
--- a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
+++ b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
@@ -657,7 +657,7 @@ LL | #[derive(Diagnostic)]
 LL |     other: Hello,
    |            ^^^^^ unsatisfied trait bound
    |
-help: the trait `IntoDiagArg` is not implemented for `Hello`
+help: the nightly-only, unstable trait `IntoDiagArg` is not implemented for `Hello`
   --> $DIR/diagnostic-derive.rs:40:1
    |
 LL | struct Hello {}