diff --git a/.changeset/sharp-dryers-try.md b/.changeset/sharp-dryers-try.md
new file mode 100644
index 000000000000..dcdbd99d0293
--- /dev/null
+++ b/.changeset/sharp-dryers-try.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: tweak "invalid assignment" compiler error message
diff --git a/documentation/docs/98-reference/.generated/compile-errors.md b/documentation/docs/98-reference/.generated/compile-errors.md
index c4989200075d..a867cfe88cb9 100644
--- a/documentation/docs/98-reference/.generated/compile-errors.md
+++ b/documentation/docs/98-reference/.generated/compile-errors.md
@@ -331,7 +331,39 @@ The $ prefix is reserved, and cannot be used for variables and imports
### each_item_invalid_assignment
```
-Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`)
+Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)
+```
+
+In legacy mode, it was possible to reassign or bind to the each block argument itself:
+
+```svelte
+
+
+{#each array as entry}
+
+
+
+
+
+{/each}
+```
+
+This turned out to be buggy and unpredictable, particularly when working with derived values (such as `array.map(...)`), and as such is forbidden in runes mode. You can achieve the same outcome by using the index instead:
+
+```svelte
+
+
+{#each array as entry, i}
+
+
+
+
+
+{/each}
```
### effect_invalid_placement
diff --git a/packages/svelte/messages/compile-errors/script.md b/packages/svelte/messages/compile-errors/script.md
index fa851cec89ea..0aa6fbed90d8 100644
--- a/packages/svelte/messages/compile-errors/script.md
+++ b/packages/svelte/messages/compile-errors/script.md
@@ -32,7 +32,39 @@
## each_item_invalid_assignment
-> Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`)
+> Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)
+
+In legacy mode, it was possible to reassign or bind to the each block argument itself:
+
+```svelte
+
+
+{#each array as entry}
+
+
+
+
+
+{/each}
+```
+
+This turned out to be buggy and unpredictable, particularly when working with derived values (such as `array.map(...)`), and as such is forbidden in runes mode. You can achieve the same outcome by using the index instead:
+
+```svelte
+
+
+{#each array as entry, i}
+
+
+
+
+
+{/each}
+```
## effect_invalid_placement
diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index 870cd9ac093d..a997eeef8d7c 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -151,12 +151,12 @@ export function dollar_prefix_invalid(node) {
}
/**
- * Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`)
+ * Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)
* @param {null | number | NodeLike} node
* @returns {never}
*/
export function each_item_invalid_assignment(node) {
- e(node, "each_item_invalid_assignment", `Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. \`array[i] = value\` instead of \`entry = value\`)\nhttps://svelte.dev/e/each_item_invalid_assignment`);
+ e(node, "each_item_invalid_assignment", `Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. \`array[i] = value\` instead of \`entry = value\`, or \`bind:value={array[i]}\` instead of \`bind:value={entry}\`)\nhttps://svelte.dev/e/each_item_invalid_assignment`);
}
/**
diff --git a/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding-this/_config.js b/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding-this/_config.js
index 524c2f161c27..ed02e0960d39 100644
--- a/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding-this/_config.js
+++ b/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding-this/_config.js
@@ -4,6 +4,6 @@ export default test({
error: {
code: 'each_item_invalid_assignment',
message:
- 'Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`)'
+ 'Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)'
}
});
diff --git a/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding/_config.js b/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding/_config.js
index 524c2f161c27..ed02e0960d39 100644
--- a/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding/_config.js
+++ b/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-binding/_config.js
@@ -4,6 +4,6 @@ export default test({
error: {
code: 'each_item_invalid_assignment',
message:
- 'Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`)'
+ 'Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)'
}
});
diff --git a/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-mutation/_config.js b/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-mutation/_config.js
index 524c2f161c27..ed02e0960d39 100644
--- a/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-mutation/_config.js
+++ b/packages/svelte/tests/compiler-errors/samples/runes-invalid-each-mutation/_config.js
@@ -4,6 +4,6 @@ export default test({
error: {
code: 'each_item_invalid_assignment',
message:
- 'Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`)'
+ 'Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)'
}
});