diff --git a/compiler/rustc_error_messages/locales/en-US/privacy.ftl b/compiler/rustc_error_messages/locales/en-US/privacy.ftl
index 97050635f45..223092a74bd 100644
--- a/compiler/rustc_error_messages/locales/en-US/privacy.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/privacy.ftl
@@ -14,7 +14,7 @@ privacy_in_public_interface = {$vis_descr} {$kind} `{$descr}` in public interfac
 privacy_from_private_dep_in_public_interface =
     {$kind} `{$descr}` from private dependency '{$krate}' in public interface
 
-private_in_public_lint =
+privacy_private_in_public_lint =
     {$vis_descr} {$kind} `{$descr}` in public interface (error {$kind ->
         [trait] E0445
         *[other] E0446
diff --git a/compiler/rustc_macros/src/diagnostics/fluent.rs b/compiler/rustc_macros/src/diagnostics/fluent.rs
index 2e7652ad333..f7d8b494ee2 100644
--- a/compiler/rustc_macros/src/diagnostics/fluent.rs
+++ b/compiler/rustc_macros/src/diagnostics/fluent.rs
@@ -187,11 +187,11 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
         for entry in resource.entries() {
             let span = res.ident.span();
             if let Entry::Message(Message { id: Identifier { name }, attributes, .. }) = entry {
-                let _ = previous_defns.entry(name.to_string()).or_insert(ident_span);
+                let _ = previous_defns.entry(name.to_string()).or_insert(path_span);
 
                 if name.contains('-') {
                     Diagnostic::spanned(
-                        ident_span,
+                        path_span,
                         Level::Error,
                         format!("name `{name}` contains a '-' character"),
                     )
@@ -205,11 +205,23 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
                 // The last case we error about above, but we want to fall back gracefully
                 // so that only the error is being emitted and not also one about the macro
                 // failing.
-                let snake_name = Ident::new(
-                    // FIXME: should probably trim prefix, not replace all occurrences
-                    &name.replace('-', "_").replace(&format!("{}_", res.ident), ""),
-                    span,
-                );
+                let crate_prefix = format!("{}_", res.ident);
+
+                let snake_name = name.replace('-', "_");
+                let snake_name = match snake_name.strip_prefix(&crate_prefix) {
+                    Some(rest) => Ident::new(rest, span),
+                    None => {
+                        Diagnostic::spanned(
+                            path_span,
+                            Level::Error,
+                            format!("name `{name}` does not start with the crate name"),
+                        )
+                        .help(format!("prepend `{crate_prefix}` to the slug name: `{crate_prefix}{snake_name}`"))
+                        .emit();
+                        Ident::new(&snake_name, span)
+                    }
+                };
+
                 constants.extend(quote! {
                     pub const #snake_name: crate::DiagnosticMessage =
                         crate::DiagnosticMessage::FluentIdentifier(
@@ -226,7 +238,7 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
 
                     if attr_name.contains('-') {
                         Diagnostic::spanned(
-                            ident_span,
+                            path_span,
                             Level::Error,
                             format!("attribute `{attr_name}` contains a '-' character"),
                         )
@@ -249,7 +261,7 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
                 match e {
                     FluentError::Overriding { kind, id } => {
                         Diagnostic::spanned(
-                            ident_span,
+                            path_span,
                             Level::Error,
                             format!("overrides existing {}: `{}`", kind, id),
                         )
diff --git a/src/test/ui-fulldeps/fluent-messages/duplicate-a-b.ftl b/src/test/ui-fulldeps/fluent-messages/duplicate-a-b.ftl
new file mode 100644
index 00000000000..9407c517045
--- /dev/null
+++ b/src/test/ui-fulldeps/fluent-messages/duplicate-a-b.ftl
@@ -0,0 +1 @@
+a_b_key = Value
diff --git a/src/test/ui-fulldeps/fluent-messages/duplicate-a.ftl b/src/test/ui-fulldeps/fluent-messages/duplicate-a.ftl
index fd9976b5a41..9407c517045 100644
--- a/src/test/ui-fulldeps/fluent-messages/duplicate-a.ftl
+++ b/src/test/ui-fulldeps/fluent-messages/duplicate-a.ftl
@@ -1 +1 @@
-key = Value
+a_b_key = Value
diff --git a/src/test/ui-fulldeps/fluent-messages/duplicate-b.ftl b/src/test/ui-fulldeps/fluent-messages/duplicate-b.ftl
deleted file mode 100644
index fd9976b5a41..00000000000
--- a/src/test/ui-fulldeps/fluent-messages/duplicate-b.ftl
+++ /dev/null
@@ -1 +0,0 @@
-key = Value
diff --git a/src/test/ui-fulldeps/fluent-messages/label-with-hyphens.ftl b/src/test/ui-fulldeps/fluent-messages/label-with-hyphens.ftl
index 84b6c3e6c00..016cbeef662 100644
--- a/src/test/ui-fulldeps/fluent-messages/label-with-hyphens.ftl
+++ b/src/test/ui-fulldeps/fluent-messages/label-with-hyphens.ftl
@@ -1,2 +1,2 @@
-some_slug = hi
+label_with_hyphens_some_slug = hi
     .label-has-hyphens = test
diff --git a/src/test/ui-fulldeps/fluent-messages/missing-crate-name.ftl b/src/test/ui-fulldeps/fluent-messages/missing-crate-name.ftl
new file mode 100644
index 00000000000..9bd035c1bba
--- /dev/null
+++ b/src/test/ui-fulldeps/fluent-messages/missing-crate-name.ftl
@@ -0,0 +1,2 @@
+with-hyphens = 1234
+test-crate_foo = abcd
diff --git a/src/test/ui-fulldeps/fluent-messages/slug-with-hyphens.ftl b/src/test/ui-fulldeps/fluent-messages/slug-with-hyphens.ftl
index 07517c9a243..86ba9a268f3 100644
--- a/src/test/ui-fulldeps/fluent-messages/slug-with-hyphens.ftl
+++ b/src/test/ui-fulldeps/fluent-messages/slug-with-hyphens.ftl
@@ -1 +1 @@
-this-slug-has-hyphens = hi
+slug_with_hyphens_this-slug-has-hyphens = hi
diff --git a/src/test/ui-fulldeps/fluent-messages/test.rs b/src/test/ui-fulldeps/fluent-messages/test.rs
index f0f35780666..256857e52a7 100644
--- a/src/test/ui-fulldeps/fluent-messages/test.rs
+++ b/src/test/ui-fulldeps/fluent-messages/test.rs
@@ -50,8 +50,8 @@ mod duplicate {
 
     fluent_messages! {
         a => "./duplicate-a.ftl",
-        b => "./duplicate-b.ftl",
-//~^ ERROR overrides existing message: `key`
+        a_b => "./duplicate-a-b.ftl",
+//~^ ERROR overrides existing message: `a_b_key`
     }
 }
 
@@ -60,7 +60,7 @@ mod slug_with_hyphens {
 
     fluent_messages! {
         slug_with_hyphens => "./slug-with-hyphens.ftl",
-//~^ ERROR name `this-slug-has-hyphens` contains a '-' character
+//~^ ERROR name `slug_with_hyphens_this-slug-has-hyphens` contains a '-' character
     }
 }
 
@@ -80,5 +80,18 @@ mod valid {
         valid => "./valid.ftl",
     }
 
-    use self::fluent_generated::{DEFAULT_LOCALE_RESOURCES, valid::valid};
+    use self::fluent_generated::{DEFAULT_LOCALE_RESOURCES, valid::key};
+}
+
+mod missing_crate_name {
+    use super::fluent_messages;
+
+    fluent_messages! {
+        test_crate => "./missing-crate-name.ftl",
+//~^ ERROR name `test-crate_foo` contains a '-' character
+//~| ERROR name `with-hyphens` contains a '-' character
+//~| ERROR name `with-hyphens` does not start with the crate name
+    }
+
+    use self::fluent_generated::{DEFAULT_LOCALE_RESOURCES, test_crate::{foo, with_hyphens}};
 }
diff --git a/src/test/ui-fulldeps/fluent-messages/test.stderr b/src/test/ui-fulldeps/fluent-messages/test.stderr
index 856642c4818..26d87430a8f 100644
--- a/src/test/ui-fulldeps/fluent-messages/test.stderr
+++ b/src/test/ui-fulldeps/fluent-messages/test.stderr
@@ -29,33 +29,57 @@ error: expected a message field for "missing_message"
   | ^^^^^^^^^^^^^^^^^
   |
 
-error: overrides existing message: `key`
-  --> $DIR/test.rs:53:9
+error: overrides existing message: `a_b_key`
+  --> $DIR/test.rs:53:16
    |
-LL |         b => "./duplicate-b.ftl",
-   |         ^
+LL |         a_b => "./duplicate-a-b.ftl",
+   |                ^^^^^^^^^^^^^^^^^^^^^
    |
 help: previously defined in this resource
-  --> $DIR/test.rs:52:9
+  --> $DIR/test.rs:52:14
    |
 LL |         a => "./duplicate-a.ftl",
-   |         ^
+   |              ^^^^^^^^^^^^^^^^^^^
 
-error: name `this-slug-has-hyphens` contains a '-' character
-  --> $DIR/test.rs:62:9
+error: name `slug_with_hyphens_this-slug-has-hyphens` contains a '-' character
+  --> $DIR/test.rs:62:30
    |
 LL |         slug_with_hyphens => "./slug-with-hyphens.ftl",
-   |         ^^^^^^^^^^^^^^^^^
+   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: replace any '-'s with '_'s
 
 error: attribute `label-has-hyphens` contains a '-' character
-  --> $DIR/test.rs:71:9
+  --> $DIR/test.rs:71:31
    |
 LL |         label_with_hyphens => "./label-with-hyphens.ftl",
-   |         ^^^^^^^^^^^^^^^^^^
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: replace any '-'s with '_'s
 
-error: aborting due to 6 previous errors
+error: name `with-hyphens` contains a '-' character
+  --> $DIR/test.rs:90:23
+   |
+LL |         test_crate => "./missing-crate-name.ftl",
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: replace any '-'s with '_'s
+
+error: name `with-hyphens` does not start with the crate name
+  --> $DIR/test.rs:90:23
+   |
+LL |         test_crate => "./missing-crate-name.ftl",
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: prepend `test_crate_` to the slug name: `test_crate_with_hyphens`
+
+error: name `test-crate_foo` contains a '-' character
+  --> $DIR/test.rs:90:23
+   |
+LL |         test_crate => "./missing-crate-name.ftl",
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: replace any '-'s with '_'s
+
+error: aborting due to 9 previous errors
 
diff --git a/src/test/ui-fulldeps/fluent-messages/valid.ftl b/src/test/ui-fulldeps/fluent-messages/valid.ftl
index 0eee4a02b96..54927430600 100644
--- a/src/test/ui-fulldeps/fluent-messages/valid.ftl
+++ b/src/test/ui-fulldeps/fluent-messages/valid.ftl
@@ -1 +1 @@
-valid = Valid!
+valid_key = Valid!